Skin mass from the left side of the face. Growing slowly for 2 years
On excision, measured 5.5 x 4.5 x 3.5cm
SUMMERS
1
2
ACVP
2021
2008
CANINE
Dog, crossbreed, 13years old, M
H&E
Perianal mass
AVALLONE
1
3
ACVP
2021
23675
FELINE
8-year-old, Male neutered, DSH cat
H&E
Nasal bleeding and deformity Biopsy
ROCCABIANCA
1
4
ACVP
2021
0
CANINE
Dog, 5 years old, M, German Shepherd
H&E
Mass in the soft palate, 6 x 8 cm
AVALLONE
1
5
ACVP
2021
0
FELINE
Cat, 15 years old, DSH
H&E
Interscapular subcutaneous mass
Subcutaneous mass with cystic areas
AVALLONE
1
6
ACVP
2021
0
FELINE
Cat, 15 years old, DSH
H&E
Interscapular subcutaneous mass
Subcutaneous mass with cystic areas
AVALLONE
1
7
ACVP
2021
0
CANINE
8-months old, Male intact dog, mixed breed,
H&E
At 6 months crusting of the right ear, progressive ulceration, thickening. After three months similar lesions in left ear.
Right ear excised (PD46)
ROCCABIANCA
1
8
ACVP
2021
0
CANINE
8-months old, Male intact dog, mixed breed,
H&E
At 6 months crusting of the right ear, progressive ulceration, thickening. After three months similar lesions in left ear.
Left ear excised (PD70)
ROCCABIANCA
1
9
ACVP
2021
0
FELINE
16-year-old Male neutered DSH cat
H&E
developed a left thoracic subcutaneous mass after vaccine injection.
Mass was excised and measured 6×7×5 cm
ROCCABIANCA
1
10
ACVP
2021
10476718
CANINE
1-year-old, SF Golden retriever
H&E
Presented for bleeding vagina
"vaginal hyperplasia"
SCHULMAN
1
11
ACVP
2021
10458244
CANINE
1-year-old dog
H&E
Acute onset vomiting and lethargy
Adhesions throughout the abdomen
SCHULMAN
1
12
ACVP
2021
10473135
CANINE
9-year-old Pharaoh hound
H&E
Tricavitary effusion with cardiac tamponade
White nodules lining the pleura, within the mediastinum, and on the pericardium and auricular appendages of the heart
Enlarged sternal lymph nodes
SCHULMAN
1
55
NEVPC
2021
10
CAPRINE
Yersinia pseudotuberculosis enteritis
Three, 2 to 3-year-old, female (1) and neutered male (2), Nigerian Dwarf, Nubian, and Boer goats
Three goats from the same farm were submitted for postmortem examination over the course of 8 days in late January to early February during an outbreak in which 5 goats died. On presentation, the goats were dull, lethargic, and inappetent, progressing to recumbency. Physical examination showed diarrhea, hypothermia, and ruminal atony. Two animals died, and one was euthanized.
The perineum, caudal thighs, and ventral tail were covered by dried tan-brown feces. The small intestine and cecum had granular serosal surfaces and were segmentally coated in thick layers of adherent yellow-tan fibrin strands. The small intestine ranged from fluid-filled and dilated with thin walls to thick-walled with obstructive luminal fibrinonecrotic casts. In the thickened segments, the mucosa of some animals was diffusely replaced by yellow-tan, friable, necrotic debris (diphtheritic membrane), while in others it was dark red, roughened and occasionally had miliary, 1-2 mm diameter, soft tan nodules. The mesentery was edematous and mesenteric lymph nodes were markedly enlarged up to 5 cm in diameter. Multifocally, the lymph node corticomedullary architecture was effaced by pale yellow purulent exudate surrounded by a thin rim of remaining tissue (abscesses).
H&E
Yersinia pseudotuberculosis is a worldwide cause of enterocolitis, lymphadenitis, and septicemia in a wide variety of wild and domestic species, and humans, most frequently reported in wild hares and ruminants.
Harvey
1
56
NEVPC
2021
11
SAND BOA
Alimentary T cell lymphoma, epitheliotropic, small cell
2-year-1-month-old, 92 g, female sand boa
The patient presented with a several months history of chronic regurgitation and weight loss.
The mucosa of the small intestine was segmentally slightly thickened.
H&E
Although once considered uncommon, neoplasia is a relatively common occurrence in reptiles, especially snakes (Effron et al. 1977; Garner et al. 2004). Out of the reported neoplasms, lymphoma is one of the more common neoplastic condition in snakes, and the presentation may vary greatly, similar to any other species. While a multicentric distribution is the most common presentation, solitary tumors have been reported including one specifically affecting the mucosa-associated lymphoid tissue of the esophagus (Ossiboff 2018). Leukemia without multicentric or solitary lymphoma has also been reported (Schilliger et al. 2011). Based on a comprehensive review of 35 lymphomas out of 326 tumors in snakes, large, blast-like cells were more commonly observed than small cell lymphoma (Garner et al. 2004).
Nakagun
1
57
NEVPC
2021
12
AVIAN
Severe trematodiasis, compatible with Cotylurus sp.
Juvenile male Black backed gull
Severe vestibular symptoms were noted that did not improve or resolve with supportive care.
The cloaca is focally expanded by an approximately 1.5 cm in diameter, thick-walled spherical out-pocketing continuous with the cloacal lumen, containing dozens of 0.5 cm-long metazoan parasites tightly adhered to the mucosa. Sharp delineation between a plump, faintly bilobed, pale pink spherical forebody and oblong pearl white hindbody is appreciable.
H&E
Based on the presence of an oral sucker, spongy parenchyma and paired ceca, those parasites were deemed most consistent with trematodes. While trematodes in aquatic birds are legion and may show a broad variety of forms, the combined sharp bisegmentation, presence of a somewhat spherical forebody containing a deep oral sucker, and cloacal location, were considered most compatible with the Strigidae family, and especially Cotylurus sp., an uncommon parasite of the alimentary tract of seagulls. The life cycle of Cotylurus sp. typically includes three free-living, and three parasitic stages. The initial egg phase is followed by emergence of a free-living miracidium, which enters a gastropod before turning into a parasitic sporocyst. Within this first intermediate host, the sporocyst produces cercariae, which penetrate a fish or leech, either of which may represent a second intermediate host fostering development of the metacercarian stage. Fisheating birds are ultimately infected through ingestion of the second intermediate host, acting as the final host in which maturation towards the adult stage occurs. With regards to the absence of additional underlying pathologic process, the neurological signs noted in this bird were considered related to the combined parasite infestation, prolonged exposure to cold, and hindered access to food.
Nelissen
1
58
NEVPC
2021
13
EQUINE
Ganglioneuromatosis, colon
8-month-old Arabian Filly
The patient presented to the referring veterinarian with a 7-month history of ill-thrift and chronic diarrhea. Histologic assessment of endoscopic duodenal biopsy samples revealed mild, diffuse, chronic, lymphoplasmacytic, and eosinophilic enteritis with villus atrophy, prompting an exploratory celiotomy 4 days later.
Multifocally scattered across the serosal surface of the ventral colon and transverse colon were innumerable, raised, moderately well-demarcated, firm, white nodules with mural infiltration. The transverse colon also had associated segmental luminal restriction.
H&E
GN is described as a poorly demarcated, multinodular-to-coalescing, intramural, benign proliferation of ganglia (i.e. neurons, glial cells, supporting cells) within the gastrointestinal system. Ganglioneuromas are also benign proliferations of ganglia but tend to be more discreet. GN occurs exclusively within the gastrointestinal system, with five reports in the small intestine, three reports in the large intestine, and one report in the gall bladder. Clinical signs associated with GN vary depending on the affected region of the gastrointestinal system. Small intestinal GN is associated with diarrhea, vomiting, inappetence, obtundation, and low body condition score. Large intestinal GN is associated with tenesmus, hematochezia, and rectal prolapse3,5. Gall bladder GN is associated with cholecystitis and cholestasis. In a previous equine case report, GN was an incidental finding with no apparent gastrointestinal clinical signs.
Champion
1
59
NEVPC
2021
14
CAMELID
Esophagitis, erosive/ulcerative, lymphoplasmacytic, multifocal, moderate, with ballooning degeneration of epithelial cells, occasional pustules, intracytoplasmic eosinophilic inclusion bodies, and vasculitis
~1-month-old, male camel calf
Sir Camelot nursed well the first week and then began with sudden weight loss. It was treated and began tube-feeding, but progressed to diarrhea, lethargy, and then recumbency. Died.
The distal esophagus has several linear bright red streaks and 25-30, approximately 3-5 mm of diameter erosions/ulcers, some covered with a brown to tan flocculent material (fibrin).
H&E
Supported by the presence of large intracytoplasmic inclusion bodies on the esophagus along the gross findings of multiple areas of ulceration along the gastrointestinal tract, the first main differential are viruses from the family Poxviridae. In this family of viruses, Bovine Papular Stomatitis and Contagious Ecthyma are considered. This last one has been reported in camels, and for which ulcers and proliferative lesions can extend into the upper gastrointestinal tract in some cases. In both cases, intracytoplasmic eosinophilic inclusions are highly suggestive of infection.
Stevenson
1
60
NEVPC
2021
15
AVIAN
Bornaviral ganglioneuritis and leiomyositis
Female Quaker Parrot
Radiographic evidence displayed a mass like object containing small mineral opacities below an enlarged proventriculus and in line with the cranial pole of the kidney.
The proventriculus and ventriculus were dilated with thinned walls for both compartments.
H&E
Proventricular Dilatation Disease (PDD) primarily affects the autonomic nerves of the upper and middle digestive tract, including the esophagus, crop, proventriculus, ventriculus, and duodenum. This disease condition has a worldwide distribution, and its name is derived from the predominant clinical sign in large parrots; namely, the dilation of the proventriculus by accumulated food as a result of dysfunction of the ventriculus. PDD is a disease across multiple species of birds particular amongst psittacines, however has been identified in other species (i.e. Canada Geese, Red-Tailed Hawks). A bornaviral etiology was implicated in more recent literature.ÊÊ
Tocco
1
61
NEVPC
2021
16
FELINE
Odontogenic myxoma
15-year-old, female, domestic shorthaired feline
This patient presented for an ossifying lesion of the lower mandible.Ê On radiographs, there was a poorly defined region of radiolucency within the mandibular bone with a smaller characteristic Òsoap bubbleÓ appearance.
This 3.0mm diameter mass was hard and tan.
H&E
Odontogenic myxomas originate from the ectomesenchyme of the dental papilla or dental follicle. Historically known as the Òjaw myxomaÓ, odontogenic myxomas are solely located within tooth-bearing regions of the maxilla and, more commonly, the mandible.3 Odontogenic myxomas are unique among ondontogenic tumors in that the they lack proliferative odontogenic epithelium. Grossly, cut sections are often gray-white, cystic, and have mucoid or slimy surfaces. Radiographically, odontogenic myxomas have a radiolucent trabecular appearance, with often ill defined borders, and a commonly reported Òsoap bubbleÓ or ÒhoneycombÓ appearance (as in this case), with possible sunburst periosteal reactions.
Hammett
1
62
NEVPC
2021
17
GOLDFISH
Ameloblastoma, gill arch
6-year-old goldfish
This goldfish presented for removal of a mass that was firmly attached to the gill arch.
A large, pink, raised, multilobular mass arises from the left pharyngeal gill arch, elevates the operculum and extends caudally.
H&E
Odontogenic neoplasms are usually incidental findings in fish. Most descriptions are of odontomas arising in the mouth, lips, and jaws. This includes angelfish Òlip fibroma,Ó which is a compound odontoma embedded in abundant collagenous stroma. There are reports of retroviral particles in the cytoplasm of stromal cells of odontomas, though a causal role has not been proven. Additionally, several reports describe epizootics and individual cases of odontogenic neoplasms, including odontomas and ameloblastomas, in multiple species of fish. The neoplasm in this case was diagnosed as a ameloblastoma, which has not been previously reported in cyprinids to the authorsÕ knowledge.
Baskerville
1
63
NEVPC
2021
18
BEARDED DRAGON
Adenocarcinoma and intravascular T cell lymphoma, colon; T-cell lymphoma, spleen and liver
Eight year old, male, intact, bearded dragon
This lizard presented with a five-month history of progressive, ulcerative dermatitis of the tail tip and hind limbs and progressive weight loss.
Necropsy revealed a multifocal to segmental thickening and yellow discoloration of the colonic wall. Attached to this area of thickening was a 3-mm-diameter, yellow, polypoid mass on the serosal surface. The colon proximal to these lesions was dilated 300-400%. The spleen was enlarged approximately 300%, and pale tan to yellow with an irregular shape that was molded around a loop of small intestine. There were multifocal to coalescing areas of yellow discoloration and pallor of the left lateral hepatic lobe.
H&E
This is the first case of intestinal adenocarcinoma reported in bearded dragons and was unique in that it presented concurrently with lymphoma. The original location of lymphoma in this case is unknown. The cutaneous lesions were pleocellular, but may have included insidious neoplastic T cells.
Argue
1
64
NEVPC
2021
19
CANINE
Salivary lipomatosis
8-year-old female spayed miniature Australian shepherd
Presented for excision of a large, soft, fluctuant mass in the left cranial cervical region, which had been present and slowly growing since May of 2018.
The mass, submitted as Òleft mandibular/sublingual salivary gland,Ó floated in formalin and measured 9 x 5.9 x 4.4 cm. It was firm, tan to brown, and was subdivided into variably-sized lobules by thin bands of fibrous stroma.
H&E
Salivary lipomatosis (also known as lipomatous/fatty infiltration of the salivary gland or interstitial lipomatosis) is a rare, benign, non-neoplastic entity in dogs that causes marked soft to fluctuant enlargement of salivary glands due to the deposition of large amounts of adipose tissue within the interstitium of affected glands. Though the cause is undetermined, the majority of cases have been associated with chronic salivary inflammation and obstructive processes.
Caudill
1
65
NEVPC
2021
1
CANINE
Spirocerca lupi sarcoma
1-year-old female spayed mixed breed dog
The patient was presented to the Penn Vet Emergency Service and transferred to the Internal Medicine Service for further evaluation of dysphagia, regurgitation, and coughing. She was adopted from India where she was originally found with her litter mates, all of which were treated for Spirocerca infections.
Two, rounded, glistening masses were visualized (one in the proximal esophagus and one near the lower esophageal sphincter).
H&E
This case was reviewed with four additional pathologists, who all agreed that the degree of pleomorphism and mitotic activity in these samples was more consistent with a sarcoma rather than fibroproliferative lesion. There was a discussion on the distinction between the advanced pre-neoplastic phase and malignant transformation, and that this differentiation is likely not possible based on the tissue provided. Spirocerca lupi is a nematode parasite that causes endemic disease in dogs in tropical and subtropical geographic regions, like certain areas of South America and Africa. Large breed hunting dogs tend to be predisposed to developing infections, likely due to the lifecycle of the parasite. The life cycle of S. lupi begins with eggs shed in the feces of the definitive host (carnivores). Eggs are ingested by the intermediate host (coprophagous beetles of numerous different species) in which they mature into L3 larvae in several months. A paratenic host (i.e. poultry, wild birds, lizards, rodents, hedgehogs and rabbits) may ingest the infected beetle, and a definitive host may become infected by ingesting the intermediate or paratenic host. Once in the definitive host, L3 larvae penetrate and traverse the gastric wall, eventually reaching the caudal thoracic aorta via various vascular routes and maturing to the L4 stage. Finally, as immature adults, the nematodes travel and encyst in the esophagus where they sexually mature and females pass eggs into the lumen of the esophagus. Adults usually encyst within the submucosa.
Amerman
1
66
NEVPC
2021
20
EQUINE
Typhlocolitis, granulomatous, segmental, severe with myriad intrahistiocytic, acid-fast, and variably Gram-positive bacteria, lymphangitis, and serositis (Mycobacterium genavense and Salmonella sp.)
23-year-old Quarter horse gelding
Oone-month history of unresolving chronic diarrhea.
The serosa of the large intestine and the cecum were covered in hundreds of dark black slightly raised variably sized plaques ranging from 0.3 cm to 2cm. The large intestinal mucosa was thickened, edematous, dark brown to black and with ten to twenty polypoid semi-firm proliferations predominantly in the cecum. The large intestinal lesions were least severe in the right dorsal colon.
H&E
Organisms within sections of the affected large intestine were closely homologous for M. genavense. Additional tissues were forwarded to the same outside laboratory for further comprehensive detection of Mycobacterium sp. via immunohistochemical and molecular tests.
KRAMER
1
67
NEVPC
2021
21
Llama
Jejunitis, lymphadenitis and hepatitis, pyogranulomatous to necrotizing with intracellular bacteria (Rhodococcus equi) and rare trematodes (liver only); peritoneum: fibrinosuppurative serositis; spleen: atrophy
11-year-old male intact llama
A 11-year-old intact male llama presented with diarrhea, inability to rise, and heavy gastrointestinal parasitism.
Severe fibrinosuppurative peritonitis presented with adhesion of intestinal loops to each other and the mesentery. A string of mesenteric lymph nodes of the jejunum was markedly enlarged and contained purulent material when cut. The jejunum had a single transmural perforation approximately 5 cm in diameter. The extensive necrosis of the surrounding jejunal wall was continuous with multifocal areas of ulceration on the mucosal surface. Smaller foci of ulceration were present in the adjacent, hyperemic mucosa of the small intestine over a ~ 15 cm long segment. The liver had myriad disseminated foci. Most foci were grey and pin-point to 1 mm in diameter and flat; fewer foci dark red brown, depressed and 2-4 mm in diameter; occasional foci pale tan, protruding and up to 3 mm in diameter.
H&E
Rhodococcus equi is, typically, a pathogen of foals leading to pyogranulomatous pneumonia with lymphadenitis, less commonly enterocolitis and intraabdominal abscesses. Virulence-associated markers of R. equi have been well established. Virulence-associated protein anti-gens (VapA or VapB, respectively) have been implicated in R. equi virulence in a number of host species including horses. In non-equid species, infections with R. equi commonly present as lymphadentitis. However, a broad spectrum of disease conditions has been described in a wide range of domestic and wild animal species, worldwide. Examples include bronchopneumonia, osteomyelitis, subcutaneous abscesses, and disseminated infection involving lymph nodes and viscera in goats in North America. and bronchopneumonia and lymphadenitis in wild boar in South America, Europe and Asia.
Löhr
1
68
NEVPC
2021
22
CANINE
Severe diffuse villous necrosis with intra-lesion bacilli, congestion, and mucosal hemorrhage
5-year-old male intact Doberman Pinscher
Found dead in its kennel with a bloated face and bloody stool.
The abdomen was markedly gas distended and contained 200 mL of blood. The duodenum, jejunum, and ileum were purple colored and markedly dilated by red-black fluid and gas.
H&E
Microscopic findings, the lesions noted grossly during postmortem examination, and anaerobic culture results from the small intestines established a diagnosis of enterotoxemia. C. perfringens is the most frequently isolated clostridial species throughout the world. This species is ubiquitous in the environment and in the intestine of mammals and birds. These diseases include enteric syndromes such as avian necrotic enteritis, lamb dysentery, neonatal hemorrhagic or necrotizing enteritis, and ovine, caprine, and bovine enterotoxemia. The pathogenicity of C. perfringens is due to a significant degree to an array of extracellular toxins produced. These toxins historically were organized into two categories, major (mouse lethal) and minor (non-lethal) toxins. The major toxins are alpha (CPA), beta (CPB), epsilon (ETX) and iota (ITX). These toxins form the basis for the classification of the individual strains into 5 toxinotypes (A-E). Alpha-toxin (CPA or PLC) is produced by all C. perfringens strains, although toxinotype A strains usually produce higher amounts than the other toxinotypes. This toxin is a zinc-dependent phospholipase C which degrades phosphatidylcholine and sphingomyelin, both components of the eukaryiotic cell membranes, causing damage tn the membrane of erythrocytes and other cells from many animal species. The net result of this action is cell lysis, by degradation of membrane phospholipids. CPA also activates several other membrane and internal cell mechanisms that lead to hemolysis. In addition, CPA activates the arachidonic cascade resulting in the formation of thromboxanes, leukotrienes and prostaglandins, which activate the inflammation cascade and produce vasoconstriction. In combination with Pergringolysin (PFO), CPA allows C. perfringens to escape macrophage phagosomes and survive in the host tissue. Acute hemorrhagic diarrhea syndrome (AHDS) is common in dogs. There are numerous terms used for this syndrome, such as canine hemorrhagic gastroenteritis, canine intestinal hemorrhage syndrome, acute intestinal hemorrhage syndrome in dogs, acute hemorrhagic diarrheal syndrome, and acute hemorrhagic enteropathy The syndrome is characterized by acute onset of hemorrhagic diarrhea and is frequently associated with vomiting and hemoconcentration. The clinical history, gross and histologic findings, and bacterial culture results in this case were classic for this condition.
Vásquez
1
69
NEVPC
2021
23
CANINE
Intestinal infarct, multifocal, severe, acute, with bacterial translocation and septic peritonitis
10 year old, castrated male, standard schnauzer dog
A pheochromocytoma was diagnosed by internal medicine on Feb 9, 2021. The tumor was removed by surgical oncologists May 3, 2021. Intestines became discolored dark grey during surgery. The patient recovered uneventfully from anesthesia but declined rapidly post-op, with continuous bloody diarrhea, regurgitation, and poor appetite.
The mesenteric arcade is dark red. There is extensive, coalescing ulceration of the small intestinal mucosal surface throughout the duodenum, jejunum, and ileum, affecting approximately 65% of the mucosal surface, with hemorrhage along the interface of normal and ulcerated mucosa. Linear ulcers are within the orad colon.
H&E
This is an unusual case of multifocal enteric infarction with profound necrosis, bacterial translocation, and peritonitis in this animal. Atherosclerosis was discovered histologically. This is a disease in the wall of blood vessels, wherein cholesterol deposits expand the tunica intima, variably associated witha granulomatous reaction, which further constructs vessel luminal diameter. This is an uncommon disease in dogs, but when present, it is highly associated with underlying metabolic disease, most commonly diabetes mellitus or hypothyroidism. Although it can be incidental, in this case there is histologic evidence of thrombosis in affected vessels, illustrated most prominently in the papillary muscle of the heart, where it is associated with focal myocardial infarction. Catecholamine release in dogs can contribute to a hypercoagulable state, and productive pheochromocytomas can release catecholamines. Between the residual effects of a recently removed pheochromocytoma, the general stressors associated with surgery of any kind, and the underlying arterial disease, this animal entered a hypercoagulable state, further evidenced by the presence of a large, organizing right atrial thrombus.
Oakes
1
70
NEVPC
2021
24
BOVINE
Abomasitis, fibrinonecrotizing and ulcerative, multifocal, moderate, with marked edema
9-day-old female Holstein calf
Farm has lost approximately 5 calves in the past week.
Within the abdominal cavity and predominantly cranially, there is approximately 5L of a light yellow, opaque, and sweet smelling liquid with abundant gelatinous light yellow to white clots. There are adhesions between serosal surfaces around the duodenum, pancreas, forestomachs, and liver, which form multiple pockets filled with the described fluid and clots. The abomasal mucosa is pale red, and the abomasal folds are mildly expanded by clear edema; there are three approximately 1.5 x 0.3 x 0.2 cm depressed areas coated with light brown material in the mucosa (ulcers).
H&E
In this very unusual case, a farm experienced acute loss of multiple very young dairy calves.Ê The third calf lost was submitted to the Louisiana Animal Disease Diagnostic Laboratory, where gross anatomic examination revealed a severe cranial abdominal peritonitis.Ê A sweet odor consistent with milk replacer was apparent upon opening of the abdomen.Ê Large pale yellow to white coagula in the abdomen were slightly rubbery with a consistency of milk curds.Ê Perforating gastrointestinal lesions were not evident grossly or microscopically.Ê Histopathology of the coagula adhered to the serosa revealed fibrin with low numbers of entrapped leukocytes and karyorrhectic debris, regionally invaded by low numbers of fibroblasts, with mild hemorrhages.Ê PCR for rotavirus, coronavirus, and BVDV were negative.Ê Aerobic and anaerobic culture of the abdominal contents were negative for bacterial growth, and bacteria or other etiologic agents were not evident histologically.Ê An additional field necropsy performed by the attending clinician on the case yielded similar gross findings.Ê The following week, it was discovered that a new formulation of milk replacer had been instituted, but the measuring instruments for reconstituting it had not been changed.Ê This resulted in the calves receiving at least twice the volume that they were supposed to receive of a formula that was twice as concentrated as it was supposed to be.Ê The farm instituted proper measuring instruments for reconstitution of the milk replacer, and no additional losses occurred.
Vyhnal
1
71
NEVPC
2021
25
CANINE
Colitis, histiocytic and ulcerative, transmural, marked, chronic, with intra and extracellular gram-negative bacilli Ð Escherichia coli
7-month-old intact female French bulldog
This animal had a history of chronic diarrhea, inappetence and weight loss.
The omentum was focally adhered to the large intestine serosa. A 4cm segment of the colon adjacent to the cecum had irregular serosal surface and was transmurally thickened up to 1cm. This segment was firm and white on cut surface, and the mucosa was irregular and dark green to brown.
H&E
Histiocytic ulcerative colitis or granulomatous colitis is a chronic syndrome that affects primarily Boxers and French Bulldogs. Infiltration of the colonic lamina propria and submucosal layers with histiocytes containing PAS positive material is a diagnostic feature of this disease. Escherichia coli was recently implicated as the etiologic agent associated with this condition. In this case, intrahistiocytic and extracellular gram-negative short rods were observed in the superficial and deep layers of the colonic wall, and were also highlighted with Giemsa and Steiner special stains. The splenic nodules described grossly contained colonies of gram-negative short rods, and bacterial culture of this organ yielded moderate growth of E. coli and Pseudomonas aeruginosa, indicating sepsis. The culture results and characteristic microscopic intestinal findings, including intralesional PAS-positive histiocytes and gram-negative short rods are supportive of E. coli as the causative agent of this histiocytic colitis.
Lima
1
72
NEVPC
2021
26
DEER
Enterocolitis, necrohemorrhagic, severe, segmental to diffuse, acute with transmural bacteria of mixed morphologies, including gram positive bacilli consistent with Clostridium sp.
Female intact white-tailed deer fawn
Over approximately 2 weeks, the rehabilitator had lost three fawns, all with similar signs including tremors and wobbly legs with rapid progression to an inability to rise. Additionally, fawns often exhibited vocalization, drooling, wide-eyes, labored breathing, and death within 3-4 hours of onset of signs.
The ventral surface of the diaphragm closest to the abomasum was coated with tan, friable, light yellow, strands of fibrinous material. Throughout the mesentery, lymph nodes were prominent and approximately 1.0 cm in diameter. The rumen, reticulum, and omasum contained mottled green to white, thick, pasty material admixed with plant fibers. Bright green material of similar consistency was in the abomasum. Most of the intestinal tract was transmurally bright red to black. Segmentally, the intestines contained gas and bright red to muddy brown, opaque liquid.
H&E
Gross and microscopic findings confirmed severe intestinal disease characteristic of toxins produced by the bacterium, Clostridium perfringens (clostridiosis). Some Clostridium spp. are normal inhabitants of the gastrointestinal tract of cervids and ruminants; however, with changes to the gut microenvironment, the organisms and the toxins they produce can flourish in the intestine, leading to disease. Such gut microenvironment changes could occur with drastic changes in feed, abnormally nutrient-rich digesta, antibiotics, reduced gut motility, and/or primary infections with other agents. The toxins produced by Clostridium perfringens, as detected in this fawn, can be absorbed into the bloodstream (enterotoxemia) and were the presumed cause of its severe clinical disease and death. In the present case, no other pathogens or underlying disease processes were microscopically evident, although the widespread and severe tissue damage in the gut may have masked concurrent intestinal infections. There was no histopathologic or laboratory evidence of infection with epizootic hemorrhagic disease virus, bluetongue virus, or cervid adenovirus. Clostridiosis is sporadically detected in both wild and farmed cervid species. Toxin entry via the gut (i.e., enterotoxemia) affects mostly young red and fallow deer, but intestinal infections associated with diarrhea also have been reported in roe deer. C. perfringens has been isolated from farmed fallow deer and red deer with rumen acidosis, enteritis, and/or colitis. A wide variety of nondomestic ruminants can be affected by enteric infection with C. perfringens toxinotypes, but significant disease most commonly is associated with type C (producing alpha and beta toxin) which causes hemorrhagic enteritis. C. perfringens type A has also been implicated as a cause of fatal hemorrhagic enteritis.
Radisic
1
73
NEVPC
2021
27
RABBIT
Intestinal adenocarcinoma
5-year-old intact male rabbit
This animal had an approximately two month history of persistent, gaseous, gastric distension with normal stools. Survey and contrast radiographs suggested an intestinal obstruction. An exploratory laparotomy was performed, and a mass was identified in the area of the duodenal-jejunal intersection, with adhesion of the colon to the serosal surface.
At necropsy, there was abdominal effusion. The omental fat was adhered to the previous surgical site, which did not have gross evidence of stricture or perforation. The left hepatic lobe contained a large cystic mass and there was a small firm nodule in the proximal duodenum.
H&E
Neoplasia of the gastrointestinal tract is consistently reported to be rare in both pet and laboratory rabbits (Oglesbee, Heatley, Turner, van Zeeland). The most commonly reported gastrointestinal neoplasm is bile duct adenoma or its malignant counterpart, cholangiocarcinoma. These are suspected to be associated with infection by Eimeria steidae, presumably due to the inflammation and hyperplasia induced by this organism (Oglesbee, van Zeeland). Other reported primary gastrointestinal neoplasms of rabbits include leiomyomas and leiomyosarcomas, as well as rare gastric and colonic adenocarcinomas (Baum, Heatley, Oglesbee, van Zeeland). In this retrospective study, 737 cases of rabbit neoplasia were diagnosed via biopsy and post-mortem examination. Forty four of the cases (44/737; 6%) were primary alimentary tract neoplasia, four of which (4/44; 9%) were intestinal adenocarcinoma. The most common primary alimentary tract neoplasm diagnosed was rectal polyp/adenoma (n=15; 15/44; 34.1%). Intestinal adenocarcinoma, oral squamous cell carcinoma, and intestinal lymphoma were the most commonly diagnosed primary alimentary tract malignancies, with 4 cases each.
Beavis
1
74
NEVPC
2021
28
EQUINE
ÊT-cell rich large B-cell lymphoma
17-year-old Rocky Mountain gelding
There was a one month history of weight loss and one week history of lethargy, inappetence and intermittent fever. Results of a complete blood count (CBC) on the farm included a neutrophilia with toxic neutrophils, hyperfibrinogenemia and hyperalbuminemia.
A 20 cm diameter, firm, white to tan, irregularly shaped mass was found within the intercolonic fold between the right ventral and right dorsal colon, immediately proximal to the diaphragmatic flexure. On cut section, the mass contained multiple, up to 4 cm diameter, foci of a thick yellow to light green fluid (pus). A focal, transmural, mucosal ulceration was noted at the site of the mass, allowing communication between the right ventral and right dorsal colon (fistula). The regional abdominal lymph nodes were enlarged (up to 4 cm diameter) and light tan.
H&E
T-cell-rich large B-cell lymphoma (TCRLBCL) is the most common type of lymphoma reported in horses and is characterized by a mixed population with varying proportions of T-cells, B-cells and other cells such as histiocytes. Infectious etiologies and/or hyperplasia are also strong differentials for these lesions due to the mixed population of cells and presence of necrosis. Definitive diagnosis of TCRLBCL based on H&E staining alone can be challenging; special stains to rule out infectious etiology and immunohistochemistry are helpful in making a final diagnosis. In this case, a fistula communicating between the right ventral and the right dorsal colon was identified, a feature that has not been reported in the veterinary literature.
Hassebroek
1
75
NEVPC
2021
29
PINE SISKIN
Severe subacute focal necrotizing and granulomatous esophagitis with intralesional bacilli and protozoa consistent with Trichomonas sp.
Three pine siskins (Spinus pinus) of unknown age (3/3), one female and two unknown sex
In March 2021, three pine siskins were submitted for necropsy via the LSU wildlife hospital within a one week period (3/9-3/15) with lethargy, inability to fly, diarrhea, and respiratory distress.
The esophagus had one or multiple tan to yellow caseous nodules/plaques on the mucosa (3/3). The spleen had multiple tan, firm nodules measuring 1 mm in diameter (2/3).
H&E
Salmonellosis is considered the cause of death of the pine siskins, and trichomoniasis also contributed to the death of the pine siskin that had this organism. Pine siskins are especially susceptible to Salmonella Typhimurium, and this bacterium can cause high mortality in this species. Trichomoniasis also can be lethal to wild birds, including pine siskins. Transmission of both Salmonella and Trichomonas is via the fecal-oral route and bird feeders play an important role in the spread of the diseases. Salmonellosis in pine siskins not only can cause high mortality in the species, but also has public health significance as humans can contract the disease through contact with sick or dead birds, bird feeders, or indoor-outdoor cats and other companion animals. Regular cleaning of the bird feeders is important, and it is recommended to take the bird feeders down during Salmonella outbreaks.
Lee
1
76
NEVPC
2021
2
EQUINE
Severe acute regionally extensive eosinophilic colitis with fibrinoid vascular necrosis and edema
13-year-old warmblood mare
Presented for colic of approximately 24 hoursÕ duration. Borborygmi were absent and the abdomen was distended but nasogastric intubation yielded no net gastric reflex. Palpation per rectum revealed a taut colonic band coursing from right to left.
At the junction of the pelvic flexure and left dorsal colon was an approximately 15 cm diameter intramural mass with distinct borders that caused narrowing of the lumen and mild obstruction. The mass extended from the antimesenteric border to the mesentery, which was also thickened.
H&E
Eosinophilic gastrointestinal disease in horses can occur as part of a multisystemic disease or may be restricted to the gastrointestinal tract. Disease restricted to the gastrointestinal tract may be diffuse or focal. Horses with diffuse eosinophilic enteritis often present with a chronic disease course including weight loss and intermittent colic, whereas focal eosinophilic disease often causes acute colic, as in this case. Focal eosinophilic intestinal disease occurs more commonly in the small intestine (often called idiopathic focal eosinophilic enteritis [IFEE] or, previously, circumferential mural bands [CMB]) but has been reported in the large colon, small colon, and rectum (segmental eosinophilic colitis [SEC]). In the large intestine, the junction of the pelvic flexure and left dorsal colon is the most common site. The pathogenesis of IFEE/SEC is unclear. Individual cases with eosinophilic granulomas, parasitic migration tracts, or infectious agents (e.g. Pythium) have been reported, but no clear association with parasite infestation or anthelmintic treatment, environmental elements, or other factors has been demonstrated for this syndrome. Lesions often contain increased numbers of macrophages and T lymphocytes, suggesting that a derangement of the inflammatory milieu plays a role. The focal form may be an acute exacerbation of the diffuse form as some horses had eosinophilic infiltrates in grossly normal intestine distant from the lesion.
Willis
1
77
NEVPC
2021
30
CANINE
Ulcerative gastritis, necrotizing, focally extensive, suppurative, marked with marked submucosal fibroplasia and hemorrhagic tortuous ectopic artery
11-year-old castrated male Labrador Retriever
5-day history of gastrointestinal bleeding, melena, and anemia. The patient vomits large volumes of blood.
The submitted sample is a 1 cm x 0.5 cm, full-thickness, folded gastric segment.
H&E
The presence of a medium-caliber artery with a wide lumen in the lamina propria and submucosa is very remarkable. Usually, blood vessels of this size are not present in the mucosa or submucosa. This lesion may be consistent with Dieulafoy's lesion observed in human patients, which is characterized by the presence of a single large tortuous small artery in the submucosa. DieulafoyÕs lesion is diagnosed in approximately 1-6% of cases of acute GI bleeding in people and is characterized by a large, aberrant, tortuous artery in the stomach (most commonly) or other parts of the GI tract.Ê To our knowledge, a lesion similar to DieulafoyÕs lesion in people has never been reported in a dog.Ê This case report describes the clinical, surgical, and histological features of a DieulafoyÕs-like lesion in a geriatric domestic canine patient.
Murillo
1
78
NEVPC
2021
31
CANINE
Mucosal myxosarcoma
9-year-old spayed female Boston terrier
The patient presented for anemia, lethargy, and melena of 10 dayÕs duration.
The submitted 14 cm segment of jejunum contained a central, 3 x 3 x 2.5 cm, area of circumferential, mural thickening that was firm, white, and multilobulated on cut surface.
H&E
The two main microscopic differential diagnoses for this patient were leiomyosarcoma and gastrointestinal stromal tumor, which were ruled out by negative immunohistochemistry for smooth muscle actin and c-kit antigens. Myxosarcomas in dogs are rare, most frequently involving the skin and with rare mesenteric, odontogenic, splenic, vertebral, cerebral, ophthalmic, cardiac, and muscular occurrences. Intestinal myxosarcoma in dogs has been alluded to in various sources; however, a published description was not located. In comparison, three reports of cecal myxosarcoma have been described in horses, with consistent histologic features to this case of atypical fibroblastic cells within an alcian blue-positive stroma. Metastasis to regional lymph nodes was present in each of the equine intestinal myxosarcomas cases.
McCullough
1
79
NEVPC
2021
32
RABBIT
B cell lymphoma
9-year-old spayed female Netherland dwarf rabbit
A 6.5-cm-diameter, firm, pale tan irregular mass extended from the tip of the cecum and effaced the vermiform appendix.Ê The mass was cracked and oozing a suppurative exudate.
Received in formalin were eight tissues up to 8 cm in greatest dimension that were processed in four blocks.
H&E
B cell lymphoma
Magnotti
1
80
NEVPC
2021
33
OCTOPUS
Hemocytic and necrotizing adenitis with intralesional cestode larvae, accessory and primary digestive glands
Wild caught, male, prickly reef octopus
This animal was caught in Florida and shipped to an aquarium for display. Transit was delayed and the animal was cold upon arrival to the aquarium.
No significant lesions.
H&E
Cestode infection in cephalopods is frequent, with many cephalopod species serving as intermediate or paratenic hosts and acting as vectors to transport them to other intermediate or definitive hosts. In general, adult cestodes are not found in cephalopods, but the tremendous diversity of larval and post-larval stages detected suggest that cephalopods remain important intermediate hosts, with further maturation occurring in elasmobranchs and fish. In cephalopods, larval cestodes most often infect the digestive tract, but may be found free in the mantle cavity, or encysted within the mantle musculature. There is also one report of an unidentified adult cestode infection in Octopus cyanea, in which the cestodes lived in the circulatory system of the arms and throughout the body, sometimes filling the entire mantle cavity. The most commonly reported cestode to infect cephalopods is Phyllobothrium spp., but cestodes from three other genera have also been identified in the common octopus (Octopus vulgaris) and include the onchoproteocephalidean Acanthobothrium spp, the tetraphyllidea Anthobothrium spp, and the trypanorhynch Nybelinia spp. While adults of Tetraphyllidea and Trypanorhynchea are found within the gastrointestinal tract of sharks, skates, and rays, their larval forms are some of the most commonly identified cestodes in cephalopods. Histologic characteristics of octopus salivary gland cestodiasis have been described in Octopus maya, and were putatively identified as Prochristianella sp.; the digestive tract was not examined in that study.
Finnegan
1
81
NEVPC
2021
34
OCTOPUS
Hemocytic anterior phakitis, multifocal, moderate, with intralesional bacteria and mild anterior uveitis
Wild-caught common octopus
This common octopus (Octopus vulgaris) was acquired from the wild when it was fully grown, and housed at a public display aquarium.Ê The animal started senescing approximately one month prior to death and was euthanized.
At necropsy, the eyes were cloudy.Ê The siphon and gills were pale pink.
H&E
Pathologic ocular lesions in cephalopods are uncommonly reported with only three cases of phakitis and retinitis documented in the literature.
Fiddes
1
82
NEVPC
2021
35
FELINE
Feline infectious peritonitis
17-year-old female spayed domestic shorthair cat
A 17-year-old female spayed domestic shorthair cat presented to NCSU-CVM repeatedly over a week for persistent and progressive anorexia of several weeksÕ duration.Ê Physical examination revealed mild dehydration, a mildly distended and painful abdomen, increased respiratory effort after handling, and a grade II/VI systolic heart murmur.Ê Abdominal ultrasound performed at initial work up revealed several abnormalities, including pancreatomegaly with presumptive pancreatitis and steatitis, cholecystic debris and common bile duct thickening (choledochitis), mild small intestinal thickening and corrugation, jejunal lymphadenopathy, and scant peritoneal effusion.
Skin, mucous membranes, and visceral fat were diffusely pale to bright yellow. Present multifocally across the surface of the pancreas, as well as throughout the adipose of the mesentery and omentum, were too numerous to count, firm to gritty, bright yellow, pinpoint to 3 x 1.5 x 0.5 mm plaque-like nodules (fat saponification). Scattered across the mesentery, splenic capsule, and the serosa of the duodenum, jejunum, ileum, colon, and stomach, were too numerous to count tan nodules ranging in size from pinpoint to 5 mm in diameter that are similar to those described in the thoracic cavity. At the level of the major duodenal papilla, the common bile duct was markedly, segmentally thickened but was patent upon applying pressure to the gallbladder.
H&E
Herein we describe the clinical, gross, and histologic features of a unique presentation of FIP in a geriatric cat. This case was considered unusual due to the age of the affected cat, associated clinical pathology, and major organs affected. First, while FIP is classically considered a disease of young cats, multiple studies have demonstrated a slight increase in FIP incidence in cats >12 years old. The reasons behind this are likely multifactorial and could include immunosenescence and/or debilitation due to concurrent unrelated disease states. Regardless of the underlying pathogenesis, antemortem diagnosis in a geriatric cat can be challenging Ð as was the case for this cat Ð considering that many other diseases (e.g. neoplasia) are more common in this age group. Second, the most significant antemortem clinicopathologic finding in this cat was marked progressive anemia, with evidence of immune-mediated hemolysis (saline agglutination, hyperbilirubinemia) and requirement of a pRBC transfusion. In this case, this finding led clinicians to prioritize more common causes of IMHA (e.g. Mycoplasma haemofelis). While some studies have identified anemia as a common finding in cats with FIP, the most recent ACVIM consensus statement on IMHA concluded that there is negligible evidence to suggest FIP causes IMHA. Despite this, given that the pathogenesis of both diseases is immune-mediated, an immunologic causative link between the two seems possible in this case. Furthermore, pancreatitis in cats has been reported in association with IMHA, and so we speculate that in this case that all three entities (FIP, pancreatitis, and IMHA) are interconnected. Third, in this case the pancreas was significantly affected. Pancreatitis is known as a possible albeit uncommon manifestation of FIP. Like FIP, pancreatitis can also be challenging to diagnose antemortem. In this case, there was elevation of amylase as well as ultrasonographic evidence to support pancreatitis, but FIP was not considered as a differential. Previous reports of FIP have failed to document ultrasonographic evidence of pancreatitis. In a geriatric cat as with this case, differential diagnoses prioritized for the ultrasonographic pancreatomegaly and pancreatitis may include neoplasia (e.g. lymphoma, pancreatic adenocarcinoma) or idiopathic pancreatitis with or without concurrent enteritis and cholangitis (i.e. triaditis). In conclusion, we document a case of confirmed FIP that presented with a constellation of uncommon clinical and pathologic features, including advanced age, IMHA, and extensive involvement of the pancreas. These features underscore the fact that FIP is truly a heterogenous disease in many regards, and that FIP should be considered as a differential diagnosis in geriatric cats with anemia and/or pancreatitis.
Schreeg
1
83
NEVPC
2021
36
NHP - CHIMPANZEE
Multifocal diverticulosis and perforation with chronic, septic, peritonitis
46-year-old female Chimpanzee
An adult female chimpanzee presented for acute decline after a 2-week history of lethargy and inappetence.
Multiple, wide fibrous adhesions were present between the cranial abdominal wall along midline and the underlying serosa / omentum. The caudal abdominal organs within the pelvis (rectum, urinary bladder, ovaries, vagina, distal colon) were consolidated by dense, concentric bands of fibrous tissue. An 18 x 12 x 7 cm pocket of ~150 ml of red, turbid fluid with multiple large blood clots was present in the caudal-right abdomen. This pocket began cranially at the cecum, extended along the right body wall forming a large pool within right-medial pelvic canal and was bounded by a 2-3mm thick gray-tan fibrovascular wall. Three large (up to 2.5 cm diameter), thin walled (regionally < 1 mm thick), diverticula were identified extending from the proximal colon. On the surface, the diverticulum directly opposite the ileo-cecal-colic junction, there was a 10 x 10 mm irregular tear which communicated with the septic pocket described above. The edges of this tear were separated at the mucosal / muscularis and slightly hemorrhagic. The intestinal material within the cecum and proximal colon was similar in color and consistency as that removed from the fluid pocket. After fixation, two additional full thickness tears were observed within the diverticula.
H&E
There was concern for a ruptured bowel in this patient with secondary septic peritonitis. Gross diagnosis and histologic evaluation confirmed antemortem perforation of the colon associated with numerous diverticula. Diverticula are defined as epithelial lined cavities derived from the mucosa that extends up to, and sometimes through the serosa. In humans over 50 years of age, the incidence of colonic diverticulosis can exceed over 50% in western countries. The exact etiology is unclear and generally considered a combination of genetics, a low fiber diet, motility and colonic anatomy / microstructure. The relatively thin regions between taenia are particularly susceptible to diverticula formation, and research models have focused on those species with prominent taenia such as rabbits and monkeys with mixed results.
ÊPresented to the referring veterinarian for lethargy, inappetance, abdominal discomfort (often after eating), vomiting, and diarrhea. At that time, a chemistry panel, barium swallow study, and fecal floatation were unremarkable. Clinical signs did not improve with empirical treatment, and 3.5 weeks later, the dog had lost approximately 15% of body weight. At that time, an abdominal ultrasound revealed diffuse circumferential thickening of the ileum up to 1.80 cm in diameter with a wall thickness of up to 0.91 cm with retention of the layered wall architecture.
The intestinal diameter ranges from 1.3 cm at the margin of the distal jejunum up to 3.5 cm along an approximately 17 cm long, thickened, firm portion of the ileum. The omentum is multifocally adherent to the ileal serosa. Within the thickened ileum, the intestinal wall is up to 8-9 mm thick with retention of wall layering and narrowing of the lumen. Within the ileal wall and along the serosa and adjacent mesenteric adipose are multifocal to coalescing, 4-10 mm diameter, firm, yellow-white nodules.
H&E
The gross and histologic appearance of the ileum are most consistent with the entity of focal intestinal lipogranulomatous lymphangitis (FLL) in dogs. FLL is considered to be a rare and severe variant of canine inflammatory bowel disease and is thought to be related to leakage of lipid-rich chyle from lymphatics within the intestinal wall. FLL has been described in two recent case series of 6 and 10 dogs (Watson et al. and Lecoindre et al., respectively) as well as a smaller older case series from the 1980s (Van Kruiningen et al.). In these studies, dogs commonly presented with chronic diarrhea, vomiting, and weight loss similar to the dog in this case. One of these case series revealed a potential breed predilection for French bulldogs, the same breed as the dog in this case. The previously reported cases of FLL frequently lacked serum biochemical abnormalities; however, a small proportion of the cases had hypoalbuminemia and were associated with protein-losing enteropathy (PLE). This dog had low normal to mildly decreased serum albumin levels which may reflect early development of PLE in this case. Abdominal ultrasound in cases of FLL typically reveals circumferential segmental thickening of predominantly the muscularis of the distal jejunum or ileum +/- ileocolic junction. Grossly, focal intestinal lipogranulomatous lymphangitis appears as a thickened and firm segment of intestine (typically distal jejunum or ileum), often with numerous small (about 5 mm diameter) firm white nodules along the mesenteric border, which is consistent with gross findings in this case. Histologically, lipogranulomas are primarily observed within the muscularis, serosa, and mesentery with lesser involvement of the submucosa. Lipogranulomas are often surrounding dilated lymphatics and consist of predominantly epithelioid and foamy macrophages with occasional lymphocytes and multinucleated giant cells, sometimes with intralesional cholesterol clefts. The mucosa often appears unaffected; thus, endoscopic intestinal biopsies are typically inadequate for a diagnosis of FLL. In this case as well as a few other reported cases of FLL, there is concurrent dilation of the lacteals in the mucosal villi (lymphangiectasia). In addition to the typical lesions of FLL, this case also exhibits minimal to moderate eosinophilic and lymphoplasmacytic inflammation throughout the other examined portions of the intestine, suggestive of underlying diffuse inflammatory bowel disease. Histologic evaluation of additional portions of the intestine besides the main lesion has not been well-described in the previous case series. The etiology and pathogenesis of focal intestinal lipogranulomatous lymphangitis is currently unknown but is thought to be related to rupture of lymphatic vessels from impaired lymphatic flow and/or injury or malformation of the lymphatic vessels. In cases of FLL, infectious causes of granulomatous enteritis, such as Pythium insidiosum, Histoplasma capsulatum, Mycobacterium, Prototheca, Heterobilharzia americana, and invasive E. coli (associated with granulomatous colitis of boxer dogs and French bulldogs) may also be considered as differentials. Histology and histochemical stains (silver stains, PAS, and Ziehl-Neelsen) as well as fluorescence in situ hybridization (FISH) for invasive E. coli were unable to reveal any underlying infectious agents in previously described FLL cases. Similarly, histology along with GMS and PAS stains in this case did not reveal any underlying infectious agents. Additionally, the macrophages within lipogranulomas did not positively stain with PAS, unlike the entity of granulomatous colitis in boxer dogs and French bulldogs. In the most recent case series, surgical resection of the thickened intestinal segment and post-operative treatment with metronidazole and tapering immunosuppressive doses of prednisolone achieved remission in 8/10 dogs, while 2/10 dogs had persistent diarrhea and were euthanized within 6 months after surgery due to severe clinical decline. At the most recent check-in about 1.5 weeks post-surgery, this dog is eating well and defecating soft to semi-formed feces 4-5 times a day with gradual improvement.
Rasche
1
86
NEVPC
2021
6
MOUSE
Marked diffuse chronic neutrophilic and lymphoplasmacytic typhlocolitis with epithelial necrosis, neutrophilic exudation, crypt hyperplasia, crypt abscesses, and intralesional Gram-positive bacilli
2-month old female mouse
Dehydration, hunched posture, weight loss, and watery, yellow diarrhea. These were NOD.Foxo1-Fl/Fl(homozygous).LCK-cre(heterozygous) (nFL) mice, a novel strain developed by a laboratory at UNC to study the role of Foxo1 in type 1 diabetes mellitus.
The colon and cecum are diffusely, moderately, transmurally thickened.
H&E
n this case, the gross and histopathologic lesions and ancillary testing are consistent with typhlocolitis due to toxigenic Clostridioides difficile (formerly Clostridium difficile) infection in an nFL mouse.
Nagel
1
87
NEVPC
2021
7
EQUINE
Focal adenomatous polyp with ileocecal intussusception, necrosis, fibrin deposition, and hemorrhage, ileum
17 year old Quarter Horse gelding
Presented for colic
At the level of the ileocecocolic junction, there was a 37cm segment of ileum everted into the cecum (intussusception). Extending from the mucosa of the affected ileum at the tip of the intussusceptum was a focal, pedunculated, multilobulated, exophytic, dark brown to dark red, friable mass measuring approximately 5 cm x 3 cm x 5 cm. The remaining mucosa of the intussusceptum was diffusely dark red and roughened with a thick, mottled brown to red fibrin mat, and the submucosa was moderately expanded by edema and was diffusely dark red. The serosa and surrounding mesentery of the involved ileal segment was mottled dark red to pale tan with multifocal petechiae. Extending from the mesentery/serosa in this region (from the serosa of the intussusceptum) was a pedunculated, mottled pale tan to red, fatty mass measuring 5 cm in diameter (lipoma). Arising from the mucosa of the cecum immediately aboral to the intussusception, was a broad based, regionally extensive, multi-lobulated, exophytic, dark brown mass measuring 10 cm x 10 cm x 2 cm. On cut surface, this mass was friable, caseous, and mottled dark yellow to brown to red to pale tan with multifocal petechiae.
H&E
Adenomatous polyps are considered to be benign neoplastic lesions typically composed of tubular and/or villous epithelial proliferations. Intestinal adenomatous polyps have been previously reported in sheep, cattle, dogs, cats, horses, and humans. Adenomatous polyps are rare in adult horses and have been described in one case of duodenal obstruction and another case of multifocal adenomatous polyposis resulting in protein losing enteropathy. The underlying cause of polyp development in horses is unknown but may be associated with spontaneous formation or genetic predisposition.
Womble
1
88
NEVPC
2021
8
LOBSTER
Necrosis, multifocal, random, moderate to severe with hemocytes and gram-negative bacteria, hepatopancreas
Young adult Caribbean spiny lobster, Panulirus argus
Increased fatalities in a local public aquarium. Mortalities spanned multiple tanks connected to the same life support system.
The hemolymph was mildly opaque and did not clot. The hepatopancreas was tan to green with multifocal small, firm white foci.
H&E
Gross and microscopic findings for multiple maladies present similarly in lobsters because of their limited ability to respond to disease and bodily damage. This lobster had significant multifocal necrosis of the hepatopancreas centered on gram-negative bacteria. Vibrio harveyi was cultured, identified initially by MALDI-TOF MS and confirmed by MLSA, nanopore and Illumina sequencing.Ê Vibrio spp. result in morbidity and mortality for many aquatic animals and V. harveyi is considered one of the most significant pathogens of cultured shrimp, resulting in necrosis of the striated tail muscle. Several other Vibrio spp. are implicated in limp lobster disease and luminous vibriosis. Laser capture microdissection and genome analysis for virulence factors and anti-resistance elements are ongoing.
Dill-Okubo
1
89
NEVPC
2021
9
CANINE
Canine _-mannosidosis
Approximately 1 year old, male, mixed breed, Canis familiaris
Initially presented with progressive stumbling, weakness, and regurgitation.
Absence of subcutaneous and inner adipose tissue and severe muscle atrophy. Severe enlargements of the dorsal and ventral vagal branches, vagosympathetic trunk, phrenic nerve, cervical nerves and dorsal root ganglia were noted. The aboral esophagus was mildly distended (megaesophagus, Abnormalities of the central nervous system (CNS) included a mild internal bilateral symmetric hydrocephalus (lateral ventricles) and white matter atrophy. The kidneys were mildly enlarged and pale. The liver was enlarged, and pale brown, with left lateral lobe liver rupture and fibrosis. Both thyroid glands, spleen, and multiple lymph nodes were mildly enlarged. Multifocal small gastric pyloric ulcers were noted.
H&E
The clinical signs in this dog were consistent with a central and peripheral neuropathy. The histological findings were consistent with a systemic storage disease. Lesions in the submucosal and myenteric plexus extended throughout the length of the gastrointestinal tract. In humans with _-mannosidosis, behavioral changes, deafness, and mental disabilities are noted as early as a few months of age with other vague neurological signs. In contrast, ruminants with _-mannosidosis exhibit a severe CNS disorder with facial and skeletal dysmorphia and neonatal death. Plasma concentration of the _-mannosidosis specific oligosaccharide was approximately 75 fold that of controls. The plasma beta-mannosidase activity was severely reduced to ~5% of controls; five other lysosomal acid hydrolase activities were increased or within their normal reference interval. Genomic sequencing of this dog's MANBA gene identified a homozygous exonic five bp tandem duplication in the penultimate exon of the MANBA gene (c.2377_2381dupTATCA) which results in a reading frame shift, altering the subsequent amino acid sequence and creating a premature stop codon. The truncated beta-mannosidase enzymeis expected to be dysfunctional. This enzyme deficiency causes the accumulation of un-degraded oligosaccharides in cells, which affect the myelination of the peripheral and central nervous systems.
Bolfa
1
90
Southcentral Division
2021
11
GOOSE
Severe, subacute, encephalitis with lymphoplasmacytic perivascular cuffing and gliosis
3-month-old, male intact, goose
Presented from a flock of 20+ animals, with 3 having already died and one other sick. The goose had three days of neurologic episodes starting on 8/6/21 including ataxia, decreased mentation, head and neck tremors, as well as anorexia and lethargy. A physical exam revealed bradycardia, weakness, BCS 3/9, increased respiratory effort, intermittent coughing, wheezing, serous nasal discharge, and diarrhea.
The goose was emaciated with serous atrophy of fat. The lateral aspect of the right 4th digit had three well demarcated, irregular, reddish ulcers ranging from 6mm to 1.5cm in diameter. A similar lesion affected the lateral aspect of the right tarsus that was covered with a dark red crust. The subcutaneous tissue of the right inguinal and sacral areas was moderately expanded by yellowish edema The middle one-third of the trachea had petechial to ecchymotic hemorrhages.
H&E
West Nile flavivirus (WNV) was detetcted via PCR , no Eastern equine encephalitis alphavirus was detected, and the histologic lesions are suggestive of WNV infection. The brain was affected by perivascular infiltrates, astrogliosis and occasional spheroids within the white matter. The eye was also affected with lymphoplasmacytic pectenitis, optic neuritis and panuveitis. The sciatic and the myenteric plexus of the ileum were affected by lymphoplasmacytic lymphoplasmacytic neuritis. The skin lesion was likely secondary to trauma related to neurologic signs.
Erwood
1
91
Southcentral Division
2021
12
CAPRINE
Severe subacute multifocal suppurative cholangitis with biliary coccidia and bacilli
1.5-week-old, female, goat
Presented for weakness, nasal discharge, and emaciation. Overnight, the goat died while hospitalized. 12 kids have died recently on the farm, and several others had been showing similar clinical signs.
The goat is in emaciated body condition has serous atrophy of the renal pelvic fat. The ventral portion of the right cranial lung lobe is dark pink to red, firm, and depressed. Multifocal, small, round, tan foci of caseous material are within the parenchyma. The affected section of lung sinks in formalin. The bile ducts have thickened walls and are filled with pale green mucoid material. The gallbladder is distended with similar material. The right middle ear contains a moderate amount of yellow pasty exudate.
H&E
The cause of death in this goat was due to bronchopneumonia caused by Bibersteinia trehalose, and the biliary coccidiosis was considered an incidental finding. Biliary coccidosis is commonly recognized in rabbits (Eimeria stiedae) but rarely reported in other species such as mink, goats, chamois, hippopotami, a pig, a calf, and a dog. While the pathophysiology is uncertain, intestinal tract, blood, or lymphatic spread have all been proposed methods of infection as sporozoites and oocysts have been found in mesenteric lymph nodes. In goats, there are two reported forms of this disease: the biliary form, which is restricted to the biliary tract and gallbladder and leads to biliary hyperplasia, fibrosis, and occasionally hepatic necrosis; and the hepatobiliary form, which is additionally characterized by intrahepatic zygotes and widespread hepatic granulomas containing oocysts. This case is an example of an early stage of the biliary form as evidenced by the lack of biliary hyperplasia, fibrosis, and necrosis. It is suspected in this case that biliary coccidiosis predisposed the goat to a secondary bacterial cholangitis. A fecal floatation yielded many Eimeria spp, and no intestinal coccidia were appreciated microscopically. One report identified Eimeria caprina and Emeria alijevi from bile of a goat with hepatobiliary coccidiosis. The microscopic morphology of this biliary coccidia is most consistent with E. caprinia.
Paulson
1
92
Southcentral Division
2021
13
CANINE
Diffuse lymphoma
10-year-old spayed female West Highland Terrier
The dog was referred for suspected nodal B-cell lymphoma based on equivocal lymph node biopsy results and generalized lymphadenopathy. Lymph node cytology was inconclusive, but the diagnosis of lymphoma was supported by flow cytometric small B-cell lymphocytosis and evidence of clonal rearrangement of the B-cell receptor via PCR. Flow cytometry, cytology, and biopsy were all suggestive of an indolent phenotype, and the patient appeared otherwise healthy with no clinical signs, so continued monitoring was elected over treatment.
A 6x7x4 cm, multilobular, well-demarcated, dark red to pale tan, firm mass effaced the cranial mediastinum and sternal lymph nodes and was firmly attached to the thoracic wall. Diffusely, there was moderate to marked enlargement of the mandibular, retropharyngeal, superficial cervical, sternal, gastric, and pancreatic lymph nodes. These lymph nodes were pale tan to dark red, semi-firm, and bulged on cut section. The spleen was diffusely enlarged with a meaty texture and was mottled pale tan to red.
H&E
Although a conclusive histologic subtype was not determined, the initially diagnosed lymphoma had many characteristics suggestive of an indolent phenotype. The patient then developed acute and severe disease caused by aggressive lymphoma which was both morphologically and characteristically inconsistent with that which was previously diagnosed. Thus, this case represents a transformation of an indolent hematopoietic neoplasm to a more aggressive form. The transformation could have happened by one of three possible mechanisms: 1) a clonal subpopulation of the indolent neoplasm acquired subsequent mutations which allowed it to transform into the more aggressive form, 2) the disseminated lymphoma was not descended from the indolent neoplasm but shared a common neoplastic lymphoid precursor, or 3) the aggressive lymphoma arose de novo and had no genetic relation to the indolent lymphoma. Genetic, chromosomal, and phenotypic comparison between the two neoplastic populations is required to differentiate between these mechanisms. Unfortunately, this analysis was not performed in this case except for confirmation of consistent expression of CD20.
Dulli
1
93
Southcentral Division
2021
14
CANINE
Osteosarcoma
9-year-old spayed female Labrador Retriever dog
This patient presented due to several subcutaneous masses on the left neck, left shoulder, ventral sternum, right thigh, and left thigh. Chest radiographs revealed several lung masses.
The mass on the left shoulder was firm, and it measured 10x8x6 cm.
H&E
At the time of biopsy and cytology, the initial diagnosis for the subcutaneous masses was a sarcoma, favoring an osteosarcoma. Alkaline phosphatase stain was performed on the cytological slides from the neck, and the neoplastic cells had small, black, intracytoplasmic granules. Unfortunately, the animal developed respiratory distress after the thoracic radiograph, and due to the poor prognosis, humane euthanasia was elected. Necropsy findings supported the diagnosis of disseminated osteosarcoma, with a primary right scapular mass and metastases to the mediastinum, peritoneum, lung, skeletal muscle, kidney, lymph nodes, liver, and heart.
Faccin
1
94
Southcentral Division
2021
15
TURTLE
Moderate, multifocal, chronic, ulcerative enteritis with epithelial hyperplasia and intraluminal acanthocephalans, jejunum
Adult female red-eared slider turtle
This turtle was brought to the Texas A&M Zoological service for removal of a fishhook in the cervical esophagus. When endoscopically examined, the turtle was discovered to have perforations in the esophagus and suspected in the stomach; plans were made for plastronotomy the following day. The turtle was found dead the following morning.
The esophagus was punctured by a 4 cm long fishhook with exit points 10 cm and 7.5 cm distal to the oral cavity, with associated fibrin and mucosal hemorrhage and necrosis. In addition, approximately ten 1.8 to 2 cm long, thin, white parasites with curled tails were spread throughout the proximal small intestinal mucosa. At the sites of infestation, the small intestinal mucosa was mottled yellow to bright red (enteritis).
H&E
The cause of death in this case was likely associated with the trauma and inflammation secondary to esophageal perforation. The intestinal parasites were incidental but provide a good opportunity to review turtle parasites, particularly as the red-eared slider is a popular pet species and is also one of the IUCN’s 100 worst invasive species.
Hines
1
95
Southcentral Division
2021
16
AVIAN
Multifocal granulomatous disease involving airsacs, lungs, heart, and serosa
Lavender Orpington pullet
Backyard flock. Owner found the bird dead and brought it to the lab that morning.
The hen was emaciated (BCS 1/9). The base of feather shafts on the neck and inguinal regions were thickly coated with lice eggs. Hundreds of living northern fowl mites were present in the feathers. The crop contained a brownish slurry with a sour odor. The pericardial sac and cranial airsacs were thickened and opaque. Multifocal, < 2 mm, slightly raised, irregular, white lesions were visible on the heart. There were variably sized (generally < 4 mm), multifocal to coalescing, white to tan, firm lesions in both lungs. The dorsal aspect of the right lung was occupied by a single firm white mass, and both sets of lungs were adhered to the body wall. The lung masses were encapsulated and comprised of concentrically layered caseous material. There was a 3 x 3 cm, solid, multilobulated to botryoidal, white to tan, slightly hemorrhagic mass adhered to the body wall, cranioventral aspect of the left lung lobe, and regionally adjacent airsacs. Smaller, similar, isolated masses were distributed on the cranial aspect of the liver capsule and were particularly numerous on the serosa of the proventriculus. The intestines were empty of digesta but contained numerous adult ascarids. The cecae were distended with firm orange cores. The ovary was immature. Ureters were distended with yellow chalky material and there were two small (< 2 mm) white masses in the right kidney.
H&E
Apperson
1
96
Southcentral Division
2021
17
NHP - BABOON
Hepatitis, necrotizing, pyogranulomatous, lymphoplasmacytic, chronic, severe with myriad amoebic trophozoites
26-year-old female baboon
Euthanized following decline condition due to severe bilateral stifle osteoarthritis with synovial osteochondromatosis, moderate dental tartar, and kyphosis with compression of vertebral bodies with bridging (spondylosis deformans).
The liver had a large 12x4x4 cm multilobulated mass with cavernous spaces filled with thick yellow material. Multiple yellow firm smaller masses (ranging from 2mm – 2cm) filled with yellow soft material were found along the edges.
H&E
The family Entamoebidae is composed of diverse protists primarily found in gastrointestinal tract of humans, nonhuman primates (NHPs) and other animals. E. histolytica species complex (E. histolytica, E. dispar and E. moshkovskii) have similar morphology but have different virulence capabilities. E. dispar is primarily an enteric pathogen and E. moshkovskii is a free-living organism. E. histolytica is reported to cause typhlocolitis and extra-intestinal abscessation in humans and NHPs. Few cases of E. nuttalli has been reported in Japanese macaques and wild rhesus macaques of Nepal. The cysts or trophozoites of all species of Entamoeba are indistinguishable on histologic examination. Typical gross lesions include necrohemorrhagic and ulcerative colitis with lumen filled with blood or fibrinonecrotic debris. Abscessation may occur in liver, lungs, kidney and brain. Histologic findings in colon include necrosis of mucosa that may extend to the muscularis mucosa and flask-shaped ulcers in colon. Trophozoites of E. histolytica are spherical (10-50 um in diameter) surrounded by a thin clear halo; have a nucleus with a central dense karyosome and chromatin plaques at the periphery; light staining, granular cytoplasm with remnants of erythrocytes and glycogen (PAS positive). Differentials for colitis in NHPs include: Shigella flexneri, Shigella sonnei, Salmonella enteritidis, S. typhimurium, Campylobacter jejuni, Campylobacter coli, Yersinia enterocolitica, Yersinia pseudotuberculosis. Differentials for necrotizing and suppurative hepatitis in NHPs include: Bacterial: Francisella tularensis, Clostridium piliforme and alphaherpesviruses, tuberculosis, coccidiodomycosis, Histoplasma capsulatum var. capsulatum, Yersinia pseudotuberculosis and Streptococcus zooepidemicus. Viral: Hepatitis viruses, Yellow fever virus, Herpes B virus, Ebola and Marburg viruses.
Shivanna
1
97
Southcentral Division
2021
18
CANINE
Marked proliferative and lymphohistiocytic endarteritis, thrombosis, and mural necrosis of the pulmonary artery with intralesional nematodes consistent with Dirofilaria immitis
8-year-old male American Bulldog/pitbull mix
Submitted as a legal case for “caught in the crossfire of a gunfight” with no medical history.
There were more than eighty long, slender, white nematodes consistent with Dirofilaria immitis in the right ventricle extending into and expanding the pulmonary artery, and at least five worms in the caudal vena cava. The lungs were diffusely firm and rubbery and failed to collapse, and off-white to pale beige with a brown-orange tinge and multiple hemorrhagic foci throughout all lobes. There was an 8 x 13 x 8mm nodule in the cranial aspect of the right cranial lung lobe and a second nodule measuring 2 cm in diameter in the middle of the right caudal lung lobe – on cut surface, both were purple-brown and spreadable (necrosis). There were a minimum of thirty heartworms measuring up to 29cm in length in the main artery of the right caudal lung lobe, and some extended into the area of necrosis. A minimum of five heartworms were also present in the right caudal mainstem bronchus. On cut surface of the right cranial lung lobe, two large vessels were enlarged and thrombosed, with heartworms incorporated in the thrombi. The left caudal lobe was similar to the right side, including a thrombus and the presence of heartworms; heartworm burdens were heavier in the caudal lung lobes. There were approximately ten heartworms in the accessory lung lobe.
H&E
Due to coincidental environmental happenings, this dog was presented as a legal case. However, gross necropsy revealed a lack of penetrating wounds. Rather, there was severe dirofilariasis and pulmonary disease, with thrombosis and necrosis of the multiple large pulmonary arteries, large amounts of blood in the bronchi along with several heartworms, and a very large volume of clotted blood in the stomach. Cause of death was determined to be a combination of exsanguination, and drowning from the blood in the airways.
Vyhnal
1
98
Southcentral Division
2021
19
EQUINE
Odontodysplasia, multifocal to coalescing, severe, with marked focally extensive hypercementosis, moderate multifocal to coalescing necrotizing and histiocytic pulpitis, periodontitis, and osteomyelitis with several cocci
2Y, F, quarter horse, equine
This mare presented with unilateral maxillary swelling. On exam, feed packing was noted in the deciduous premolar #606. Further evaluation of the swelling via diagnostic imaging revealed an impacted and abnormally oriented maturing second premolar #206 associated with a multilocular cystic structure.
The maxillary width is expanded twice normal by an impacted and malformed tooth #206 and an associated multilocular cystic structure (not identifiable on submitted slide). Tooth #206 is approximately half the normal length, crescentic, angled approximately 45 degrees off the eruption axis, and oriented apical-palatine to occlusal-buccal with the developing pulp horns forming nonparallel structures that wrap back apical-buccal. The multilocular cystic structure around tooth #206 measures up to 3x3x1cm, unilaterally expands the maxilla, and has an empty lumen with a smooth tan surface. Tooth #606, while in the process of physiologic exfoliation, also has a loss of the infundibulum with replacement by brown-green foreign material (feed packing).
H&E
Odontodysplasia is rarely reported and is characterized by the disruption of normal dentinogenesis and results in abnormally shaped and often impacted teeth. There are two types of odontodysplasia - focal and regional. While focal odontodysplasia has been described in veterinary species, regional odontodysplasia refers to a human-specific entity of unknown cause where the teeth in an entire quadrant of the mouth are malformed; regional odontodysplasia has not been adequately described in any veterinary species. Focal odontodysplasia is typically trauma-induced, which alters the orientation of the enamel organ resulting in an abnormally shaped, frequently impacted or un-erupted tooth that is characterized by a dysplastic proliferation of the odontogenic germinal tissues and dental matrices (dentin, enamel, and cementum). Other causes of disruption to the enamel organ (such as infection, irritation, or other cause of inflammation) may result in a similar dysplastic proliferation.
Schwarten
1
99
Southcentral Division
2021
1
AVIAN
Moderate, multifocal to coalescing, subacute, lymphoplasmacytic and histiocytic, periportal to random necrotizing hepatitis with intracellular protozoal merozoites, macrogamonts, and microgamonts
Adult female house sparrow
This sparrow was part of a small, wild-caught research colony. It and another male sparrow in a separate cage were found dead within 12 hours of one another with no previous clinical signs reported.
Multifocally throughout the serosal surface of the jejunum were small aggregates of fibrin and the jejunal and colonic walls were expanded by a moderate amount of edema, consistent with a fibrinous coelomitis and potentially an enteritis. A section of liver is on the submitted slide.
H&E
In addition to the hepatic changes, a severe protozoal enterocolitis, splenitis, and pneumonia were appreciated, and coccidial organisms were appreciated in all tissues except the spleen. The morphology and distribution were most consistent with Atoxoplasma spp. Real-time PCR (rtPCR) was performed on the liver for Toxoplasma spp. and Chlamydia psittaci. Both were negative, while rtPCR for Atoxoplasma spp. on the liver was positive. The other affected sparrow displayed similar lesions and had identical rtPCR results. Atoxoplasma spp. are considered a junior objective synonym of Isospora, however more recent investigation has suggested it is more closely related to Eimeria spp. The syndrome of atoxoplasmosis is currently most accurately described as systemic isosporosis. Infection is considered endemic in wild birds, being found in all continents except Antarctica, and can cause acute fatal disease when birds are stressed, immunosuppressed, or have other concurrent infections, particularly in captive passerines. These parasites have a direct life cycle and are transmitted by ingestion of infective oocysts, though there is some evidence for transmission via a mite in house sparrows. The parasite undergoes asexual reproduction in the intestine and reticuloendothelial system, resulting in systemic spread, primarily to the liver, though other organs may be involved. Sexual reproduction occurs primarily in the intestinal tract, though sexual stages have been demonstrated occasionally in some species, including house sparrows. Clinical signs are nonspecific and include inappetence, weight loss, diarrhea, lethargy, and ruffled feathers. Antemortem diagnosis can be difficult because strictly enteric Isospora oocysts are indistinguishable from those which cause systemic isosporosis. Serial blood smears are required to detect the parasite within mononuclear inflammatory cells. Despite the difficulties of taxonomic classification, systemic isosporosis represents an important disease of captive passerines with the potential to cause major morbidity and mortality events in captive passerines.
Bacon
1
100
Southcentral Division
2021
2
CAPRINE
Severe, multifocal, acute tubular necrosis and degeneration with abundant intratubular oxalate crystals and occasional intra-tubular granular pigment (oxalate nephrosis and pigmentary nephrosis)
7-year-old, male castrated, domestic goat
This pet goat was apparently healthy two days prior to presentation. He became reluctant to stand and was lethargic, at which point he was taken to a local veterinary clinic. The owners believed their goat was poisoned since someone left a package of lamb chops on their porch the previous day to taunt them. Upon physical exam, the goat was non-ambulatory and slightly obtunded. CBC and chemistry revealed increased BUN and creatinine, as well as increased creatine kinase, LDH, and a slight neutrophilia. Clinical signs worsened during the hospital stay, and the patient passed away.
Transparent, yellow fluid was found in the abdomen, thorax, and pericardial sac. Systemic icterus was apparent. Multiple organs showed pallor, primarily the kidneys, heart, and brain. The liver was swollen with an enhanced reticular pattern. The rumen contained plastic bags and large roots. Lice were seen on the skin, and whipworms were found in the cecum.
H&E
Histologic changes and toxicologic testing in this case led to a diagnosis of ethylene glycol toxicosis. Ethylene glycol toxicosis is not common in ruminants, as compared with dogs and cats, although there are a few reports. The large amount of calcium oxalate crystals in this case, particularly in the brain, was a unique finding. Calcium oxalate crystals typically form following ethylene glycol ingestion. Insoluble calcium oxalate forms following gastrointestinal absorption of ethylene glycol, where it precipitates or crystalizes in vessel lumens, particularly in the kidney, and rarely in the brain. Histologically, large deposits of oxalate crystals can be seen in renal tubular lumens, tubular epithelial cells, and the interstitium of the kidney. Under polarized light, these crystal deposits characteristically appear birefringent, shaped like prisms, and arranged in sheaves.
JACOBSON
1
101
Southcentral Division
2021
3
BOVINE
Moderate, multifocal, chronic, lymphoplasmacytic and histiocytic ganglionitis with neuronal loss and intracytoplasmic viral inclusion bodies, omasum
6-month-old Wagyu bull calf
The calf was treated for sepsis 5 months prior to presentation. The calf was lethargic and weak for several days. On presentation, the calf was stuporous and dehydrated with injected sclera and hyperemic mucous membranes. Fecal staining was prominent on the tail and perineum, and the body condition was poor. Neurologic signs included horizontal nystagmus, decreased pupillary light reflex, and seizures. During treatment, the animal became comatose and arrested. The calf was revived with CPR, but soon became agonal and died.
Diffusely, the lungs were mildly firm and uncollapsed, while the cranioventral right lung lobe was dark red to purple. The tracheobronchial, lumbar, iliac, and mesenteric lymph nodes were mildly enlarged. The pyloric wall was mildly thickened. Multifocally, segments of the jejunum were dark purple, dilated, and thinned. The meninges were moderately congested.
H&E
The diagnosis of rabies was made with fluorescent antibody testing at the Texas Department of Health and immunohistochemistry. No bite wounds or trauma to the skin was noted, and the origin of the infection remains unclear. The lesions in the brain were typical for rabies, and viral inclusion bodies were numerous. Inclusions were also apparent in the adrenal gland and salivary gland. The changes in the lungs were attributed to bronchopneumonia.
Landsgaard
1
102
Southcentral Division
2021
4
EQUINE
Ameloblastoma
9-yr-old Quarter Horse gelding
The horse presented with a mandibular mass that rapidly and progressively grew over the course of six weeks. On external examination, a large firm swelling was noted beneath the tongue. Radiographs revealed a large, invasive, and lytic mass that encompassed the rostral mandible to the level of both mandibular canines. A rostral mandibulectomy was performed, and the rostral mandible was submitted.
A 12x11x10 cm rostral mandible including canine teeth with an approximately 8x7x5 cm, firm to hard, round, symmetrical, tan to red mass was submitted. The mass encompassed the mandible and protruded ventrally. On cut surface, the mass was tan to yellow, firm to hard, heavily cavitated, and effaced surrounding alveolar bone.
H&E
The location and gross appearance of this mass were highly suggestive of an odontogenic neoplasm. Other differentials included an odontogenic cyst, osteoma, ossifying fibroma, osteosarcoma, fibrosarcoma, and squamous cell carcinoma. Odontogenic neoplasms in horses are uncommon, and there is no known breed or sex predilection. Masses often present as slow growing and nonpainful swellings within the maxilla or mandible. Odontogenic neoplasms are classified by tissue of origin, and the types identified in horses include ameloblastoma, ameloblastic odontoma, ameloblastic carcinoma, odontoma, and complex odontoma. Ameloblastoma is classified based on odontogenic epithelium with absence of pulp ectomesenchyme and mineralized dental matrix. Histologically, odontogenic epithelium is classified by stellate reticulum and palisading of basilar epithelium with antibasilar nuclei and a basilar clear zone. Neoplastic cells are often arranged in plexiform ribbons, islands, anastomosing trabeculae, and “ink drop” structures. Ameloblastomas in horses are more common in the mandible than the maxilla.Odontogenic neoplasms tend to be benign, locally invasive, expansile, and cause alveolar and cortical bone lysis with displacement of teeth. The exception is the ameloblastic carcinoma, which has been shown to have a higher degree of malignancy and greater rate of metastasis. Treatment for odontogenic neoplasms include complete surgical excision, and prognosis is generally good. Local recurrence with incomplete margins has been reported.
Lui
1
103
Southcentral Division
2021
5
CANINE
Moderate, multifocal, chronic, neutrophilic, histiocytic, and plasmacytic epicarditis with marked multifocal epicardial fibrosis and mesothelial hyperplasia, with onion skin cysts consistent with Hepatooon americanum
Adult, male intact, mixed breed dog
The patient presented for evaluation of hyporexia and weight loss of approximately one month duration and progressive abdominal distension and labored breathing of approximately two weeks duration. Point of care abdominal and thoracic ultrasounds revealed tricavitary effusion. Cytologic examination of the peritoneal and pleural fluid were consistent with a modified transudate and transudate, respectively. A 4Dx Plus SNAP test was negative. The patient failed to respond to supportive care and continued to decline, thus the owners elected humane euthanasia.
The peritoneal cavity, pleural cavity, and pericardial sac contained marked, moderate, and mild amounts of serosanguineous to straw-yellow, clear fluid, respectively (tricavitary effusion). Multifocally, the parietal pleura lining the diaphragm and intercostal muscles, visceral pulmonary pleura, pericardial sac, and epicardium were moderately to markedly thickened, white, opaque, and firm (fibrosis). The right cranial and right middle lung lobes were adhered to the body wall by a marked amount of fibrosis. The apex of the left ventricle was adhered to the pericardial sac by a 1 cm diameter band of fibrosis. Multifocally, mesothelial hyperplasia covered the caudal lung lobes, epicardium of the right auricle, and mediastinum. There was mild endocardiosis of the mitral valve. The liver was diffusely and moderately enlarged with rounded margins (hepatomegaly) and a heterogeneously pale tan to dark red parenchyma on cut section (chronic passive congestion).
H&E
Canine hepatozoonosis is a tick-borne disease in the southeastern and south-central United States caused by Hepatozoon canis or Hepatozoon americanum, although infection with H. americanum is diagnosed more frequently. The vector and definitive host of H. canis and H. americanum are the brown dog tick, Rhipicephalus sanguineus, and the Gulf Coast tick, Amblyomma maculatum, respectively. Dogs are infected by ingestion of an infected tick containing mature oocysts. Sporozoites are released from oocysts in the dog’s small intestine after exposure to bile, penetrate the intestinal wall, and disseminate to target tissues by mononuclear cells where the organisms undergo merogony. The primary target tissues for H. americanum are cardiac and skeletal muscle, whereas H. canis prefers hematopoietic tissue including bone marrow, spleen, and lymph nodes. Within primary target tissues, H. americanum develops in its host cell within “onion skin cysts” eventually forming a meront that ruptures releasing numerous merozoites. Unlike H. americanum, H. canis does not form “onion skin cysts”, and instead forms distinctive “wheel-spoke” meronts containing numerous micromerozoites. In dogs infected with H. americanum, release of merozoites in the heart and skeletal muscle results in pyogranulomatous inflammation and vasculitis. In this case, the protozoal “onion skin cysts” in the cardiac and skeletal muscle are consistent with H. americanum. Although myocarditis is not evident in the examined sections, areas of cardiomyocyte loss with replacement by fibrosis and mineralization are observed, which may be secondary to historic inflammation caused by H. americanum. The findings in the pericardium and epicardium are suggestive of chronic constrictive pericarditis and epicarditis. Constrictive pericarditis is rare in dogs and cats, and causes identified include metallic foreign bodies, coccidioidomycosis, and actinomycosis. Severe cardiac dysfunction and impaired diastolic filling eventually result in congestive heart failure and death if not treated. Even though H. americanum is not identified in the pericardium and epicardium, the presence of neutrophilic and histiocytic inflammation in the epicardium, lymphoplasmacytic inflammation in the pericardium, and lack of other findings suggest H. americanum may be the cause of the chronic inflammation and fibrosis observed, leading to constrictive pericarditis and biventricular heart failure in this dog.
Milliron
1
104
Southcentral Division
2021
6
RING-TAILED LEMUR
Multifocal, mild, acute necrotizing hepatitis with intrahistiocytic and free protozoa
2.4 kg, adult, neutered male ring-tailed lemur
The lemur was lethargic, inappetent, depressed, and developed a cough an hour before death. Two other lemurs in the colony exhibited similar signs and also died.
The liver was diffusely pale tan. The lungs were diffusely dark red and mildly heavy and wet (congestion and edema). Foamy fluid was within the trachea. A lymph node at the root of the mesentery was mildly enlarged, measuring 2x1.5x1 cm. The kidneys were diffusely dark purple. The abdominal cavity adipose tissue was mildly yellow.
H&E
Toxoplasmosis is a worldwide disease cause by an apicomplexan intracellular coccidia, Toxoplasma gondii. Felids are the definitive hosts, whereas a variety of warm-blooded animals including humans, bear, deer, pigs, moose, bison, marine mammals, marsupials, birds, and small mammals serve as intermediate hosts. The presentations and mortality of this disease vary greatly depending on the immune response and susceptibility of the species affected. Marsupials (particularly macropods), New World monkeys, and lemurs are highly susceptible to fatal acute disseminated toxoplasmosis. They typically develop enteritis, necrotizing mesenteric lymphadenitis, hepatitis, interstitial pneumonia, and/ or pulmonary edema.
Neupane
1
105
Southcentral Division
2021
7
CANINE
Sertoli cell tumor with vascular invasion and seminoma
5-year-old MN German Shepherd
The dog had a history of non-pruritic alopecia along the left pelvic limb and around the prepuce, pronounced mammary glands with hyperpigmentation around the nipples, a persistently decreased lipase, and suspected exocrine pancreatic insufficiency (EPI). He was treated with Apoquel and cephalexin by the referring veterinarian with no improvement. The dog was cryptorchid as a puppy. When he was neutered, his cryptorchid testicle was unable to be retrieved. He reportedly had two abdominal surgeries to locate the cryptorchid testicle, but the owner was unsure if it was ever retrieved.
A 6.5x6x5 cm, firm, round, smooth testicle and epididymis with twisted spermatic cord and pampiniform plexus was submitted in formalin. The testicular parenchyma was completely expanded by an encapsulated, pale tan to red, soft, cystic mass. The pampiniform plexus was expanded (edema).
H&E
Testicular neoplasms are the second most common tumor in the canine, affecting mainly middle age to older dogs. The 3 most common testicular tumors are interstitial cell tumors (Leydig cell tumors) (58%), seminomas (23%), and Sertoli cell tumors (19%). They can be solitary or multiple, as in this case. These tumors are almost always benign. However, if metastasis does occur, nodules in the spermatic cord, scrotal lymph nodes, and abdominal organs may be evident. Cryptorchid testicles have a higher incidence of Sertoli cell tumors and seminomas. The right testicle seems to be predisposed to retention, which increases the risk of tumorigenesis. Castration remains the treatment of choice for these tumors and is often curative.
Zakers
1
106
Southcentral Division
2021
8
FELINE
Multifocal to coalescing, severe, chronic, lymphohistiocytic and neutrophilic pancarditis with cardiomyocyte degeneration, necrosis, and loss, and moderate interstitial and endocardial fibrosis
10-year-old, female spayed Domestic Shorthair cat
The cat acutely vocalized, vomited, and began dragging his hind legs. The owner reported that the cat was making a “gurgling” noise in the car. The cat presented for euthanasia laterally recumbent with a gallop rhythm on auscultation. The cat went into respiratory arrest and was euthanized.
The heart was diffusely and moderately enlarged. The left ventricular free wall myocardium was thickened, and the left ventricular lumen was narrowed. Three thrombi were identified within the lumen of the abdominal aorta. The cranial most thrombus measured 3x0.5x0.4 cm and was directly caudal to the diaphragm. The next was 4.5 cm caudal to the first thrombus, measured 5x3x3 mm, and extended 1 mm into the left renal artery. The most distal thrombus measured 7x4x3 mm and was 4 cm caudal to the second thrombus, adjacent to the iliac arteries.
H&E
The patient’s clinical history is consistent with the multiple emboli in the abdominal aorta, presumably secondary to blood flow turbulence. Clinical suspicion of underlying cardiac disease was confirmed with the identification of a myocarditis. Investigation for Bartonella sp. was confirmed via PCR on formalin-fixed paraffin-embedded tissue.
Barton
1
107
Southcentral Division
2021
9
CANINE
Severe, multifocal to coalescing, subacute, necrotizing and lymphohistiocytic meningomyelitis with lymphoplasmacytic perivascular cuffing, edema, and intraneuronal and intrahistiocytic amastigotes
5-year-old neutered male Pit Bull Terrier
The dog presented to the referring veterinarian for acute hindlimb paraplegia bilaterally and urinary and fecal incontinence. He demonstrated pain on palpation of the thoracolumbar spine.
Multifocally throughout the cervical and lumbar spinal cord were small areas of dark red material (hemorrhage) that dissected along white matter tracts.
H&E
Trypanosomiasis, a disease caused by numerous species of the protozoal parasite Trypanosoma, affects a wide range of mammals and can manifest in different clinical forms due to its high genetic diversity. The parasite is endemic in several Latin and South American countries, as well as Asia, Africa, the Canary Islands, and parts of the southern United States. Trypanosoma cruzi is the etiologic agent associated with Chagas disease or American trypanosomiasis, which affects an estimated 7-8 million people annually across 21 countries. The natural life cycle of the protozoan requires an arthropod vector in the family Reduviidae (Rhodnius spp., Panstrongylus spp., and Triatoma spp.), also known as kissing bugs. While feeding on a mammalian host, kissing bugs transmit infectious metacyclic trypomastigotes via defecation in or around cutaneous wounds or mucous membranes, allowing access to the host bloodstream. Once in systemic circulation, trypomastigotes can infect various host cells and form amastigotes in tissues or infect other arthropods that feed on host blood. Other routes of infection include iatrogenic transmission via contaminated needles or consumption of infected meat. Reported mammalian hosts include humans and a wide range of domestic and wildlife species including dogs, coyotes, cats, raccoons, opossums, armadillos, wood rats, skunks, capybaras, coatis, small marsupials, horses, buffaloes, camelids, cattle, and other livestock. Due to the close interaction between peridomestic dogs and humans, infected canids may serve as sentinels for surveillance of human infections since dogs are considered an important reservoir host.
Broughton
1
108
Southcentral Division
2021
20
AVIAN
B cell lymphoma, proventriculus, ventriculus, small intestines, coelom, serosal surfaces
Adult (unknown age) sun conure
Patient presented for difficulty breathing, anorexia, and dyschezia. Physical exam revealed a distended coelom, thin body condition, pectoral muscle atrophy, muffled heart sounds on auscultation, and dyspnea. Whole body radiographs revealed right, cranial displacement of the ventriculus, decreased serosal detail, gas within the intestines, and decreased air sac space to the paired abdominal and caudal thoracic air sacs.
The intestines were pale, thickened, severely distended, and surrounded by caseous material. Abdominal organs were adhered.
H&E
Lymphoma is the most common round cell neoplasm of psittacines, and is likely the most common neoplasm in this group of animals (Nemeth et al., 2016). A recent review of lymphoma in psittacines found that B cell lymphoma is the most common immunophenotype. B cell lymphomas were statistically more common in the gastrointestinal tract, similar to the case presented here (Gibson et al., 2021). This is likely due to the putative tissue of origin, gut-associated lymphoid tissue. Grading schemes for lymphoma are not available in psittacines, and mitotic counts or other factors have yet to be correlated with prognosis. Most cases present at necropsy, and it is likely that this diagnosis carries at least a poor prognosis. In this animal, lymphoma was associated with foreign body coelomitis, likely secondary to transmural infiltration of the intestines by neoplastic cells, resulting in intestinal rupture.
Gray
1
164
AAZV
2021
10
AVIAN
Severe, multifocal to coalescing, acute, fibrinonecrotizing, hemorrhagic, and heterophilic enteritis with crypt loss and vasculitis
Juvenile female Western crow
This bird was found dead with 3 others during the course of a large mortality event in wild corvids (crows and ravens) in the first few weeks of August, 2020.
The intestinal loops are segmentally moderately dilated, and the serosal and mucosal surfaces are mottled dark green to red.
H&E
A large number of crows and a few ravens (almost 90) were submitted from the grounds of the San Diego Zoo Safari Park over a one month period through August of 2020, most of which were fledged juveniles found dead or moribund. Consistent lesions included severe necrohemorrhagic enterotyphlocolitis, fibrinonecrotizing splenitis, and poor body condition. Additional, less consistent lesions included depletion of lymphocytes in the bursa of Fabricius, myeloid hyperplasia in the bone marrow, and acute renal tubular degeneration and necrosis (possibly dehydration/shock-related). The findings are consistent with those attributed to avian orthoreovirus, which has been reported in American corvids as early as 2001 and was more recently described in a retrospective review of crow mortalities in New York. Classically, outbreaks of the virus in crows have occurred during winter months, lending it the name “winter mortality of crows.” This particular event was unusual in that it occurred in late summer, however it appeared to be associated with large numbers of gathered crows (roosting areas) based on subjective observation, which is a known prerequisite for epizootics. Secondary bacterial infections (especially bacterial enteritis) and sepsis were common sequelae in many crows, and some cases had coinfections with hemoparasites, Aspergillus sp., and avian poxvirus.
WONG
1
165
AAZV
2021
11
CHEETAH
Severe diffuse subacute necrotizing enteritis with crypt necrosis and marked lymphoid depletion and necrosis (parvovirus)
2 month 25 day old, male, cheetah
This cub began separating itself from its dam and siblings. It was lethargic, inactive, and severely hypothermic (< 87°F) with bloody, liquid diarrhea. After 7 hours of supportive care (heating, subcutaneous fluids, IVC LRS with KCL and dextrose, IV Ceftiofur, and metronidazole), the temperature increased to 101.4°F. However, the cub’s condition rapidly declined and it died spontaneously less than 12 hours following onset of clinical signs.
The gastric fundic mucosa had multifocal dark red-black areas (ulcerations) and the pyloric mucosa was hemorrhagic. The duodenum and jejunum were thickened with dark red-black areas on the serosa and mucosa. The cecum contains pasty green-black material, and the colonic mucosa had paintbrush hemorrhages.
H&E
Parvoviruses are single-stranded, non-enveloped, DNA viruses which are ubiquitous, highly contagious, and naturally infect a wide range of animal species. Those within Parvovirinae cause disease in vertebrates including canids, felids, rodents, birds, fish, and humans with proven potential for cross-species transmission. Feline panleukopenia virus (FPLV) is one of the most common diseases of domestic cats and is known to infect domestic and wild felids, raccoons, mink, and foxes. Canine parvovirus emerged as a variant of FPLV in the 1970s leading to a highly deadly pandemic of canids worldwide, and eventually underwent genetic changes that allowed this new variant to re-infect feline hosts. Thus, felids are susceptible to both FPLV and CPV, although disease with CPV tends to be milder than with FPLV. In immunologically unprotected animals disease is rapid and death can occur within 24 hours of onset despite aggressive treatment.
The skunk was observed alive and dragging itself through the front yard of a private home owner in Prince Edward Island (Canada) on September 16th, 2020. It was found dead shortly after the initial observation and was frozen and submitted to the Canadian Wildlife Health cooperative on October 6th, 2020 for necropsy.
The right lung lobes are dark red, firm, and wet. There is a focus of blood and mucus adhered to the mucosa in the pyloric region of the stomach. The stomach contains numerous nematodes (Physaloptera sp.).
H&E
Skunk Adenovirus-1 (SkAd-1) is an emerging disease in North American wildlife and was first identified in a free-ranging striped skunk (Mephitidae) in Ontario in 2015. SkAd-1 has been subsequently identified in free-ranging wild porcupines (Erethizon dorsatum), gray foxes (Urocyon cinereoargenteus), a captive pygmy marmoset (Callithrix pygmaea) and African pygmy hedgehogs (Atelerix albiventris). Most adenoviruses are considered to be species-specific; whereas SkAd-1 infects a diversity of families, including Mephitidae, Hystricidae, Canidae, Cebidae and Erinaceidae. The reason for this host promiscuity is currently unknown and may relate to genetic variability between host viral genomes. The prevalence of SkAd-1 and the method of transmission among free ranging wildlife are unknown at this time. In some wildlife rehabilitation centers, positive SkAd-1 cases have been shown to survive the disease following treatment and were later released back into the wild.
CLARK
1
167
AAZV
2021
13
SKUNK
Segmental to circumferential necrotizing, lymphocytic, plasmacytic arteritis, renal artery; Multifocal, mild to moderate lymphocytic, plasmacytic interstitial nephritis and pyelitis; membranous glomerulopathy
Adult female skunk
Brought to a Northern California rehabilitation facility. After 4 days of care, she was euthanized for “progressive neurologic disease” including ataxia and impacted anal glands.
The anal glands were turgid.
H&E
There were three distinct lesions in this kidney, but all are attributed to a skunk-specific amdoparvovirus SKAV infection. We have performed in situ hybridization (ISH) on a series of skunk cases, including the case presented here (unpublished results, Pesavento laboratory). SKAV causes multi-systemic disease that only partially overlaps (sp. kidney) that of the archetype Aleutian Mink Disease virus (AMDV) in host mink, where the most common reason for renal failure is persistent infection leading to a hypergammopathy and immune complex deposition within glomeruli. Aleutian disease can include interstitial nephritis but is only very rarely associated with arteritis, whereas in skunks, in addition to consistent findings like renal interstitial inflammation, SKAV can be associated with arteritis (in any tissue), pneumonia, meningitis, dermatitis, glossitis, enteritis, and hepatitis. In this skunk, ISH of SKAV demonstrated viral nucleic acid within the arterial wall in regions of necrosis, and although sparse in this specific case, SKAV is also present within the lymphocytic, plasmacytic interstitial nephritis in many infected skunks. The basement membrane thickening could be, in part, a reaction to hypoxia (from arterial and arteriolar induced infarction) or could also include, as has been demonstrated in minks with AMDV, an immune complex deposition that is sequelae to plasmacytosis and hypergammaglobulinemia. No biochemistry was available in this case but the hyaline casts within tubules and Bowman’s space suggest protein loss through the glomerulus. How and whether each of these lesions contributed to renal compromise is unknown. This skunk, like most from the rehabilitation facilities, was neurologic, and had a lymphocytic plasmacytic meningitis, with few cerebral vascular cuffs. The reason for euthanasia was progressive neurologic decline in an animal that is part of the endemic cycle for rabies in CA. This type of presentation biases the population we examine at necropsy, so the actual impact of SKAV infection across the US on morbidity and mortality in free-ranging skunks is speculative.
PESAVENTO
1
168
AAZV
2021
14
RED PANDA
Severe, chronic, multifocal to coalescing lymphohistiocytic and necrotizing myocarditis
7-year-old female red panda
Had been clinically healthy and acting normally the previous day, but was found dead in the morning.
Necropsy revealed scattered 2- to 3-mm-diameter nodular white foci in the myocardium.
H&E
We attribute this case of myocarditis to infection with a novel, species-specific Amdoparvovirus recently described in red pandas. No other infectious agents were seen on routine (H&E) or special stains, and in situ hybridization (ISH) with Red Panda Amdoparvovirus (RPAV)-specific probes demonstrated abundant viral nucleic acid in areas of inflammation. Although specific cell targets are difficult to identify without double-labeling studies, in these lesions virus appears to localize in endothelial cells, histiocytes, and possibly cardiomyocytes. The latter would be particularly surprising given that parvoviruses require active cell division for replication of their genomes, but cardiomyocytes in mature animals are generally considered ‘post-mitotic.’
ALEX
1
169
AAZV
2021
15
RABBIT
Moderate to severe, acute, multifocal, necrotizing hepatitis
Five Lionhead rabbits ranging in age from 9 months to 3 years old were received from a rabbit rescue.
The submitted rabbits exhibited variation in clinical signs, ranging from no clinical signs to lethargy and difficulty breathing.
Grossly, all five rabbits had appropriate subcutaneous and visceral adipose stores. Only one of the five had blood on the pelage. Four of the five rabbits had reddening of the tracheal lining and two had serosanguineous thoracic effusion. All submitted rabbits had lungs that were mottled red to dark red. Three animals had livers that were multifocally pale tan and one with military red pinpoint foci throughout.
H&E
The gross and microscopic findings were suspicious for rabbit hemorrhagic disease virus (RHDV). Additional testing was warranted and needed for definitive diagnosis. RHDV2 is a reportable Foreign Animal Disease (FAD) in Georgia and was confirmed by ELISA and RT-PCR tests, at NVSL/FADDL, as positive for RHDV. The cause of this condition is a calicivirus with two types- 1 and 2. Type 2 is currently spreading in the US and to the best of our knowledge had not previously been reported in Georgia.
MCHALE
1
170
AAZV
2021
16
ELEPHANT
Severe vascular and myocardial necrosis, degeneration, and hemorrhage with intranuclear endothelial inclusion bodies, heart
10-year-old male African Elephant
This 10-year-old male African elephant had been diagnosed and treated over the last week for elephant endotheliotropic herpesvirus (EEHV) infection. It had chronic anemia for several years. After several days of rapidly progressing debilitation, it went down in the elephant restraint device and died, despite antiviral treatment.
Heart: Severe diffuse transmural hemorrhage, Pulmonary artery, lung, gastrointestinal tract serosa and mucosa, conjunctiva, oral mucosa: Moderate multifocal hemorrhage, Intestine: Moderate intramural edema, Bone marrow, spleen: Red blood cell depletion
H&E
The histologic findings are consistent with elephant endotheliotropic herpesvirus (EEHV) infection. In this case, EEHV-2 was isolated. Elephant endotheliotropic herpesvirus (EEHV) is a double stranded DNA, beta herpesvirus that causes an acute hemorrhagic syndrome (EEHV-HD) that mostly affects young Asian elephants. Studies of Asian and African elephants have shown that most Asian elephants carry strains EEHV1b, EEHV4 and EEHV5, while African elephants carry EEHV2, EEHV6 and EEHV7. Despite its widespread presence in African elephants, there have been only 13 confirmed cases of EEHV in African elephants with an approximately 50% mortality rate, and only EEHV2 has been associated with these cases (as in this case). EEHV is known to infect endothelial cells, causing edema, hemorrhage, and coagulopathies, with capillary endothelial cells being the most affected. The heart is also often severely affected. Nonclinical African elephants may have cutaneous papillomas along the trunk and lymphoid hyperplasia in the urogenital mucosa and lungs. Currently, it is not known why some EEHV-infected elephants develop EEHV-HD, while others do not. The cause of chronic anemia in this elephant was not determined, but there was a marked decrease in the bone marrow in the samples examined.
LEWIS
1
171
AAZV
2021
17
SEAL
Diffuse large B cell lymphoma, immunoblastic subtype, tracheobronchial lymph node
Male pup northern elephant seal
Upon presentation, he had linear ventral skin fold ulcers, a mild leukocytosis and moderate lymphocytosis, and elevated GGT and alkaline phosphatase. The ventral fold dermatitis progressed despite antibiotic treatment, and cytology revealed numerous mostly rod-shaped bacteria, granulocytes, and small to large lymphocytes. Acute phase protein measurements and protein gel electrophoresis were suggestive of a polyclonal gammopathy most consistent with an inflammatory process. The marked leukocytosis and lymphocytosis continued with sudden thrombocytopenia, increased BUN, and elevation in other liver biomarkers. Blood smears revealed several lymphocytes with “flower-like” nuclear morphology, as well as large lymphocytes with increased nucleus: cytoplasm ratios with fewer small to intermediate lymphocytes, segmented and band neutrophils, and erythroid precursors. While in care, the animal’s mentation and hydration had initially improved however ultimately declined in the last week of care. Euthanasia was elected based on the clinical condition as well as the cytologic, hematologic, and serum biochemical results.
All lymph nodes were markedly enlarged, firm, bulging and homogenous on cut surface. The tonsils, spleen and thymus were also markedly enlarged and firm. The jejunum, ileum, and most notably the colon had dark red, thickened, corrugated mucosa with distinct white firm nodules. There were also multiple linear ulcerations of the ventral abdominal skin folds with granulation tissue and minimal fibrinosuppurative exudate, as well as a thickened multinodular and congested urinary bladder mucosa.
H&E
Two NES male pups within the last year (one from the 2020 pup cohort and one from 2021) presented with similar clinical presentation as well as clinicopathologic features, with one featured in the present case. The necropsy, histopathologic and immunohistochemical findings were also similar for both cases with few variations. Based on the canine World Health Organization (WHO) classification system for canine lymphoma, both were diagnosed as a diffuse large B cell lymphoma (DLBL) which is the first report of this disease in northern elephant seals (NES) (Valli et al., 2011). Lymphoma has previously been reported in pinnipeds including harbor seals (HS, Phoca vitulina), a northern fur seal pup (NFS, Callorhinus ursinus), California sea lions (CSL, Zalophus californianus), and a harp seal (PG, Pagophilus groenlandicus) (Colegrove et al., 2010; Malberg et al., 2017; Stedham et al., 1977; Stroud & Stevens, 1980; Venn-Watson et al., 2012). Most of the cases were in adults, but a few were in pups or juveniles such as in these cases (Stedham et al., 1977; Stroud & Stevens, 1980). In contrast with the present cases, lymphoma in many CSLs and one HS was restricted to the intestines, and those intestinal cases were primarily comprised of intermediate neoplastic lymphocytes of T cell origin and had more prominent epitheliotropism with lesser involvement of the lamina propria or submucosa when compared to the intestinal involvement in these NES pups (Colegrove et al., 2010; Malberg et al., 2017). Cases of multicentric lymphoma when characterized by IHC were B cell in origin similar to this case (Stedham et al., 1977; Stroud & Stevens, 1980; Venn-Watson et al., 2012).
MARTINEZ
1
172
AAZV
2021
1
CLAM
Disseminated neoplasia of presumed hematogenous origin, gills, labial palps, connective tissues of the digestive tract, kidney, and multiple sinuses and vessels of the visceral mass and foot
An approximately 1.5-year-old, female, hard clam
These animals were relatively unremarkable and were not exhibiting any abnormal behaviors to suggest disease.
The shell length was 6 cm and the shell height was approximately 5 cm. Subjectively, the animal appeared to be a reproductively active female and there appeared to be mild mantle recession.
H&E
A neoplasia of presumed hematogenous origin (i.e. hemocytic or hemic neoplasia), a leukemia-like disease, was identified in this population of hard clams. In this animal, the neoplasia was considered disseminated and found in the connective tissues, vessels, and multiple sinuses, with significant progression of the disease and destruction of gill architecture. This condition is one of the most commonly described neoplastic processes of invertebrates and it has been described in numerous bivalve species.1 In soft shell clams (Mya arenaia) it is widely accepted that the disseminated neoplasia is caused by direct transmission of neoplastic cells that are transferred from infected to naïve individuals through the water column.2 This contagious hemocytic neoplasia has been of significant concern in the northeast United States and Dr. Roxanna Smolowitz (Aquatic Diagnostic Laboratory, Roger Williams University) has been conducting routine yearly monitoring and has witnessed increasing mortality in those cultured populations. This year in Cedar Key, FL, two additional individuals with early progression of the disease have been identified during our monitoring (n=3, from a population of 160 animals examined thus far). At this time, it is unclear if these animals represent de novo development of the disease or potential transmission from interstate transport of clams from the northeast United States. To date, no significant problems subsequent to infectious disease have been identified in culture clams from Florida waters; however, the clam culture industry in Florida is currently dependent on this single species, and continued investigation and surveillance is warranted.
MILLER
1
173
AAZV
2021
2
INSECT
Necrosis and loss, transabdominal, segmental, with myriad intracoelomic fungal hyphae and conidia
Adult, male, periodical cicada
This 17-year periodical cicada from Brood X (aka “Brood 10”) emerged in Maryland in late May 2021. During this emergence, up to 1.5 million cicadas per acre emerged from the ground as nymphs, climbed trees (or other vertical structures) with large, clawed forelimbs, and metamorphosed into adults. Adult cicadas, which are the world’s loudest insects, proceeded to fly erratically in unfathomable numbers with deafening lawnmower-like noises (produced from abdominal drums known as tymbals) to attract females for mating. This animal was found moribund in the author’s (EC) front yard and was euthanized with formalin.
Posterior segments of the animal were absent and displaced by large, soft, white, powdery material that extended into the posterior aspect of the coelom.
H&E
Periodical cicadas (Magicicada spp.) are insects from order Hemiptera, which are true bugs. They have one of the most spectacular life histories of any animal, having either 13-year or 17-year life cycles, the latter of which is the longest of any insect. They spend 13 or 17 years underground as nymphs, and then emerge in incredible numbers, metamorphosing into adults that mate and oviposit in trees over a 2- to 4-week period, during which time they make deafening sounds using their drum-like abdominal membranes called tymbals. Periodical cicadas form mixed species cohorts called broods that cluster geographically and temporally. Brood X (also known as “Brood 10” or “the Great Eastern Brood”) is a brood of 17-year periodical cicadas that emerges throughout the eastern United States and includes three species: Magicicada septendecim, Magicicada cassinii, and Magicicada septendecula. Brood X is the largest brood of 17-year cicadas and emerges at a density of up to 1.5 million animals per acre. Magicicada septendecim is the largest species of periodical cicada and is native to the Eastern United States. Massospora spp. are fungi in the subphylum Entomophthoromycotina, which includes nearly 300 pathogenic species of fungi that are important pathogens to arthropods. Most fungi in this subphylum, including Massospora spp., are highly host-specific (Duke et al. and Hajek et al.). Massospora cicadina infects periodical cicadas during their emergence and modifies the sexual behavior of the adults in order to maximize fungal spore dissemination (Macias et al. and Boyce et al.). Massospora fungi are the only pathogen known to affect adult periodical cicadas (Cooley et al.). The objective of this work is to present histologic lesions of a Massospora sp. infection in Magicicada septendecim. The aim is to provide reference material for veterinary pathologists examining insects using bright field microscopy.
CORBIN
1
174
AAZV
2021
3
FROG
Perkinsiosis, disseminated
Free-ranging leopard frog tadpole
The submitted specimen was part of a research investigation of Perkinsus-like organisms in amphibians of central Florida. Tadpole was found alive, euthanized, and the carcass was submitted formalin fixed.
The liver was swollen and tan-yellow.
H&E
In recent decades, there has been a significant decline in amphibian populations. Reasons for the accelerated drop in amphibian populations are multifactorial, and infectious disease has been shown to play a key role. Several pathogens, including Batrachochytrium sp. and Ranavirus, are well-documented as causative agents that contribute to the decline in amphibian populations worldwide. As research continues to better characterize these population-reducing morbidity and mortality events, novel infectious organisms are discovered. Perkinsea (also referred to as dermomycoides, dermosporidiosis, Perkinsus-like organism, and alveolate pathogen), is one such novel organism that is responsible for increased morbidity and mortality in tadpoles of ranid frogs and other amphibian species. Perkinsiosis is an emerging disease that has been implicated as the third-most common infectious cause of morbidity and mortality among anuran amphibian species. Perkinsea are currently classified as alveolate protozoa, though the classification of this organism has been disputed. The life cycle of the organism and the pathogenesis of the disease are not well understood at this time. Age, species, and environmental and seasonal factors are thought to play a role in pathogenesis and severity of disease. Clinical signs in affected ranids are nonspecific and range from lethargy, abdominal distension, and ventral hemorrhage to sudden death. Gross lesions may be absent, but when present include cutaneous erythema, cutaneous and visceral petechiation, ventral edema, ascites, and organomegaly. The liver, spleen, kidney, and pancreas are the most commonly enlarged organs and are often discolored. Histologically, numerous tissues may be infiltrated and effaced by high numbers of Perkinsea organisms. Organisms are both intra and extracellular and have two morphologies. The first population is 4-6um in diameter, round, and well-demarcated with a thin, deeply basophilic capsule and an amphophilic to palely basophilic center. The second population is 2-3um in diameter, round, and well-demarcated with a less prominent capsule and an amphophilic to eosinophilic center. Correlating with gross findings, the liver, spleen, and kidney tend to be most severely affected with replacement of at least 60% of the parenchyma by Perkinsea organisms. Other tissues affected to a lesser extent include the pancreas, gill, heart, gastrointestinal tract, eyes, central nervous tissues, skeletal muscle, and connective tissues with replacement of at least 25% of the parenchyma by Perkinsea organisms. Mild tissue degeneration and necrosis is occasionally seen in affected tissues, but inflammation is often not a prominent feature of these lesions. Histochemical stains such as Gomori’s methenamine silver stain (GMS) and Periodic-acid Schiff (PAS) can be used to highlight the Perkinsea capsule. Histochemical stains such as Giemsa can be used to highlight the center of Perkinsea organisms. Quantitative PCR assays developed for use on a wide range of anuran tissues are available as an ancillary diagnostic tool as well.
MAISEL
1
175
AAZV
2021
4
SNAKE
Epidermitis, necroulcerative and granulocytic, chronic, multifocal to coalescing, moderate, with intralesional hyphae and arthroconidia, moderate epidermal hyperplasia, subepidermal clefting, and intracellular edema
Adult, male, tentacled snake
This animal was the last specimen in the group and was found dead. The snake had been shedding continuously, was reported to be covered in white spots, and had recently lost a tentacle. This was one of 53 tentacled snakes with a similar history that died in two of the zoo’s collections between 1973 and 2021.
The skin contains innumerable individual white scales and scattered clusters of white scales, accounting for less than 10% of the body as a whole, and most abundant just caudal to the head. The affected scales are often slightly raised or thickened and rough. The skin of the head is diffusely gray and easily sloughs.
H&E
Necroulcerative and granulocytic fungal epidermitis with intralesional hyphae and arthroconidia morphologically consistent with Paranannizziopsis spp. was identified in this adult tentacled snake. PCR performed on a fungal isolate from skin and targeting the ITS2 region confirmed infection by Paranannizziopsis crustacea. This animal was one of 124 tentacled snakes submitted for necropsy over 48 years. Fifty-three snakes in this group were diagnosed with fungal dermatitis, with intralesional fungal elements morphologically consistent with Paranannizziopsis spp. Both Paranannizziopsis crustacea and Paranannizziopsis australasiensis were identified in multiple cases between the two collections.
MACK
1
176
AAZV
2021
5
SNAKE
Severe, regionally extensive, necrotizing hepatitis with multiple granulomas and intralesional fungal hyphae
Adult female massasauga
This wild massasauga was from a population in Clinton County, Illinois with a long-term history of ophidiomycosis. In December 2020, this snake was observed above ground and basking instead of brumating underground. It was captured and transported for evaluation on December 29. On presentation, this individual had significant skin lesions consisting of crusting and necrotic scales, especially involving the cloaca. Some thickened caudal coelomic contents were appreciated on palpation.
The liver was dark red with sharp margins and contained a focal, pale tan, firm nodule within the parenchyma.
H&E
Ophidiomycosis or snake fungal disease (SFD) is an infectious disease of wild and captive snakes caused by the ascomycete Ophidiomyces ophidiicola. First reported in eastern massasaugas (S. catenatus) in 2008 it has since been documented in over 30 free-ranging and captive species of snakes in the United states and Europe, including many threatened or endangered species. Infections have been reported in wild and captive snakes throughout the eastern and midwestern United States and Canada, as well as in captive snakes in Great Britain, Europe, and Australia. Recently, there have been reports of the pathogen in snakes in Idaho, Oklahoma and Puerto Rico, as well as the first documented cases in Asia earlier this year. Ophidiomycosis was confirmed in a wild red-banded snake (Dinodon rufozonatum) and wild Chinese cobra (Naja atra) in Taiwan, as well as two captive colubrids in Japan. Given that cases are being recognized globally and its implication in population declines of timber rattlesnakes (Crotalus horridus) in New England and eastern massasaugas, ophidiomycosis is considered a disease with the potential to negatively impact conservation of free-ranging snakes as well as those in managed care. Disease presentation and severity can vary significantly between species and individuals, but most commonly presents as a fungal dermatitis. Clinical signs and lesions range from accelerated ecdysis cycles, to mild superficial dermatitis with hyperkeratosis, crusts and scale loss to chronic multinodular dermal and subcutaneous inflammation that in severe cases may cause disfigurement of the face and/or oral tissues. Mild cases with superficial dermatitis may naturally resolve with successive rounds of ecdysis; however, severe infections can be fatal.
HUFFMAN
1
177
AAZV
2021
6
TORTOISE
Rhinitis, exudative and hyperplastic, granulocytic and lymphocytic, severe, with associated spiral-shaped bacteria (Helicobacter sp.)
Adult, female, free-ranging gopher tortoise
The animal was submitted lethargic and depressed, unable to open its eyes, and in thin body condition with bilateral nasal discharge.
The gopher tortoise was in extremely thin body condition with muscle and fat atrophy. Both eyes were sunken and there was concave deformation of the nares bilaterally with a small amount of mucoid discharge.
H&E
Bacteria of the genus Helicobacter are found in diverse host species, including reptiles, but the clinical implications of Helicobacter infections in tortoises are not well understood. This case is one of a group of cases in which a novel mortality-associated Helicobacter species was identified in free-ranging and rehabilitating gopher tortoises (Gopherus polyphemus) in Florida, United States. Histologic changes associated with the gopher tortoise Helicobacter species were predominantly present in the nasal cavity. Spiral-shaped organisms were plentiful in this individual (as highlighted by Warthin-Starry staining). However, this tortoise did not receive antemortem antimicrobials. In tortoises with a history of antimicrobial therapy, while similar nasal inflammation was noted histologically on postmortem examination, spiral shaped bacteria were rare to absent. In tortoises with suspicious clinical signs for nasal helicobacteriosis and a history of antimicrobial therapy, PCR and/or cytologic evaluation of nasal discharge may be critical for a definitive diagnosis. While no Mycoplasma/Mycoplasmopsis was detected in this individual, mycoplasmosis should always be considered as a differential in tortoises with upper respiratory tract disease. Evaluation of the nasal mucosa is an essential component of a tortoise necropsy, and samples should always be evaluated histologically.
OSSIBOFF
1
178
AAZV
2021
7
TURTLE
Moderate heterophilic nephritis with intratubular myxozoan spores and multifocal tubular necrosis and mild chronic granulomatous tubulointerstitial nephritis with intralesional trematode eggs
Adult male common snapping turtle
Presented with major trauma to the face and lower mandible after being hit by a motor vehicle. The turtle was anesthetized for reconstructive jaw surgery with a combination of alfaxalone and isoflurane for approximately 2 hours, however; during the recovery period the turtle went into irreversible cardiac arrest and died.
H&E
Myxozoans are microscopic metazoan endoparasites previously classified as protozoa and recently reclassified as members of the Phylum Cnidaria. Little is known about the life cycle and physiology of this group of organisms. Myxozoans are characterized by 1-13 polar capsules that contain polar filaments, a nucleated sporoplasm, 2-13 shell valves with or without caudal processes, and occasionally a vacuole. In many cases, infection with myxozoans is considered incidental and not associated with disease, however some myxozoans are highly pathogenic and can cause tissue destruction and morbidity and mortality particularly in fish. Myxozoans use a polar filament, ejected upon contact with host mucin, to attach to the host. The polar filament contracts to bring the myxozoan spore and the host into close proximity where spores inject cytotoxic contents into the host cell.
Womble
1
179
AAZV
2021
8
AVIAN
Trichomonal ingluvitis and esophagitis, hyperplastic and necrotizing, generalized, marked, chronic
Common redpoll (Acanthis flammea), adult, female
On April 8th 2021, this common redpoll was found alive on a deck in Prince Edward Island (Canada) and was unable to fly. It appeared puffed up, and seemed to be breathing heavily. It was submitted to the Atlantic Veterinary College wildlife service for treatment where fluids were administered and it was held overnight. The redpoll was found dead on the following morning in its cage.
There is generalized marked bilateral atrophy of the pectoral muscles and a complete absence of subcutaneous and internal body fat reserves. There is diffuse mild thickening of the walls of the esophagus and crop.
H&E
Trichomonosis, caused by Trichomonas gallinae, was first detected in free ranging finch species (family Fringillidae) in the United Kingdom in 2004, and in eastern Canada in 2007. Since that time, T. gallinae has been detected in numerous free ranging Fringillidae species around the world. T. gallinae is a protozoal organism that is a part of the normal flora of the upper gastrointestinal tract of Columbiformes, particularly rock doves, where it results in the disease commonly known as “canker”. Cankers are large, caseous plaques within the wall of the upper gastrointestinal tract that are the result of hyperplasia and necrosis of the mucosa in response to infiltrating T. gallinae. Inflammation and necrosis of cankers is frequently compounded by secondary bacterial infections and infiltration of trichomonads into deep tissues and other organ systems including the liver and brain. Trichomonosis in raptors is known as “frounce” and is directly related to birds of prey feeding upon infected Columbiformes, particularly those in peri-urban or urban environments.
BOURQUE
1
180
AAZV
2021
9
AVIAN
Severe, multifocal to coalescing, necrotizing hepatitis with intracytoplasmic hepatocellular, intraendothelial and intrahistiocytic hemoprotozoal schizonts and megaloschizonts
Adult, female greater sage grouse
This individual is part of geographically and genetically isolated population from Baker County, Oregon (northeast Oregon). Via radio collar, she was last heard alive during a telemetry flight the day before her mortality signal. The body was found next to a sagebrush 2 days after her mortality signal was heard.
The nasal sinuses were diffusely dark red and very mildly to mildly thickened. The proventriculus and ventriculus were filled with bits of sagebrush leaves. The intestines were partially filled with viscous dark brown-dark green digesta.
H&E
The PCR and genetic sequencing results suggest that these organisms belong to novel lineages. While further sequence analysis is pending, this species of Plasmodium and Leucocytozoon do not appear to be similar to reported species of Plasmodium and Leucocytozoon in the greater sage grouse, which include Plasmodium pediocetae and Leucocytozoon lovati. These previously reported haemosporidian species were also not previously found to be associated with overt signs of clinical disease in the birds in those studies. The high similarity in the sequence between the Leucocytozoon species in this case, and other species of grouse/related Galliformes suggest that the greater sage grouse may be the natural host for it. The sequence of Plasmodium species in this case was more similar to birds from other orders. This raises the possibility that the greater sage grouse is not the natural host for it and thus immunologically naïve and susceptible to clinical infection. Alternatively, given that haemosporidians in this population of greater sage grouse has not been as extensively studied/looked into, this could be a previously undetected species for which the grouse is the natural host for. In other avian species, increase in cases of infection and clinical disease due to Plasmodium and Leucocytozoon species has been postulated to be associated with increased exposure in vectors (dipteran insects) associated with increase in temperatures and humidity, and landscape change in native habitats, stress, and concurrent infection with other diseases. Increasing temperatures in Oregon have resulted in increasing numbers of insect vectors as well as the numbers increasing earlier in the year. It is thus possible that this increased exposure to vectors has played a role here. Plasmodium species and West Nile virus also share a similar insect vector (Diptera: Culicidae), and the latter is a reported cause of morbidity and mortality in free-ranging greater sage grouse populations. Concurrent infections could thus increase the likelihood of clinical disease due to haemosporidian infections in this species. Additional studies looking into these various factors as well as the role of pathogens in this near- threatened species would be useful in determining this.
CHONG
1
181
Southcentral Division
2021
10
AVIAN
Multisystemic lymphoplasmacytic ganglioneuritis with severe pancarditis
10-month-old Rose-breasted Cockatoo
The bird presented for seizure-like activity and a 4/5 heart murmur. A CT scan revealed poor bone density, increased fat stores, and an enlarged liver indicating potential nutritional deficiencies, increased caloric intake, and a lack of exercise.
Throughout the myocardium of the right, and less severely the left, ventricles were several multifocal to coalescing, pinpoint to 5 mm diameter, firm, white, slightly raised foci. The crop was moderately dilated and contained a large amount of thick, white to tan feed material. The proventriculus was mildly dilated and flaccid.
H&E
PCR and immunohistochemistry of the heart were both positive for avian bornavirus (ABV), the known etiologic agent for proventricular dilatation disease (PDD). In addition to the lesions described above, other findings included lymphoplasmacytic ganglioneuritis in the jejunum and colon, lymphoplasmacytic perivascular encephalitis and choroid plexitis in the cerebrum, and lymphoplasmacytic inflammation in the thymus and pancreas.
CLONTZ
1
182
NEVPC
2021
3
CANINE
Adenocarcinoma with carcinomatosis (abdomen) and widespread metastasis (liver, multiple lymph nodes, diaphragm, pericardium); gastrointestinal stromal tumor (GIST)
13-year-old male neutered Border collie
The patient presented for dry heaving/vomiting, lethargy, decreased appetite. Serosanguinous pleural effusion, hemorrhagic on cytology is present. Abdominal ultrasound showed suspect intestinal mass and carcinomatosis. Owner elected to proceed with euthanasia.
At gross examination a severe acute hemorrhagic pleural and abdominal effusions and carcinomatosis are present.
H&E
Given the histomorphologic features of the neoplasm in the pancreas and the similarity to the multifocal metastases, this most likely represents a primary pancreatic adenocarcinoma with carcinomatosis. The neoplasm in cecum is morphologically distinct and is multifocally infiltrated by invading islands of the carcinoma. Immunohistochemistry confirmed it as a gastrointestinal stromal tumor (GIST).
Finesso
1
195
AAVLD
2021
1
RABBIT
Tularemia - necrotizing hepatitis and splenitis
H&E
1
196
AAVLD
2021
2
TORTOISE
Intranuclear coccidiosis
H&E
Lee
1
197
AAVLD
2021
3
CANINE
Pseudorabies
H&E
THOMAS
1
198
AAVLD
2021
4
EQUINE
Intestinal mycobacteriosis
H&E
Lima
1
199
AAVLD
2021
5
EQUINE
Halicephalobus nephritis
H&E
PILLAI
1
200
AAVLD
2021
6
CANINE
Metastatic Digital Chondrogenic Melanocytic Tumor
H&E
TEODORO
1
201
AAVLD
2021
7
BOVINE
Otitis
H&E
Kleinhenz
1
202
AAVLD
2021
8
MINK
SARS-CoV-2 pneumonia
H&E
CLAYTON
1
203
AAVLD
2021
9
FELINE
Pyogranulomatous intestinal leiomyositis and suspect vasculitis (Bartonella henselae)
Pyogranulomatous rhinitis and cellulitis (Actinobacillus lignieresii)
H&E
Gonzalez-Viera
1
208
AAVLD
2021
14
RABBIT
Caliciviral hepatitis (RHDV2)
H&E
Streitenberger
1
246
NEVPC
2022
26
ALPACA
Cervical spinal cord 1-2: Mild, multifocal Wallerian degeneration with multifocal, random meningeal mineralizing granulomas and intralesional degenerate nematodes
16-year-old, 46 kg, male Huacaya alpaca
The alpaca was housed with another alpaca and lived in close proximity with wild boars. He had previous “suspect episodes of meningeal worm”, which were never confirmed, but were treated with monthly ivermectin for the last three years. A week before presenting to necropsy, the animal started to present with a base wide stance and posterior paresis. Despite treatment with fenbendazole and oxytetracycline, the clinical signs progressed to recumbency and hence the animal was euthanized.
Unfortunately, the degenerate nature of the nematodes in this case did not allow confident assessment of the morphology. Based on the host (alpaca), limited morphology of degenerate nematodes, and knowledge of aberrant migration, the list of differential etiologic diagnoses included Lamanema chavezi (Trichostrongyloidea), Parelaphostrongylus tenuis (Metastrongyloidea), Onchocerca sp. (Spiruruida), Strongylus vulgaris (Strongyloidea), Stephanurus dentatus (Strongyloidea), Angiostrongylus cantonensis (Metastrongyloidea), Elaphostrongylus cervi / rangiferi (Metastrongyloidea), Baylisascaris procyonis (Ascaridida), and Ascaris suum (Ascaridida). The presence of cuticular structures resembling longitudinal ridges (synlophes) was suggestive of this nematode belonging to the Trichostrongyloidea group, hence L. chavezi was prioritized. However, other nematodes, including P. tenuis could not be ruled out on morphology alone.
Ancillary testing was pursued, which included fecal floatation of feces collected during the necropsy and from another alpaca in the same housing, and PCR. From the feces of the current case, a single, approximately 35 µm diameter nematode egg with a thin, clear shell was identified, consistent with a strongyle-type egg. No eggs were found in the feces of the housemate. A wide-range PCR targeting the ITS2 region of nematodes was conducted on DNA extracted from formalin-fixed, formical-treated, paraffin-embedded tissue, but this did not result in amplification.
Lamanema chavezi is a Trichostrongyloidea nematode that is found mostly in South American camelids (Cafrune et al. 2009). However, they have been reported in llamas and alpacas in New Zealand (McKenna et al. 2011), and in a llama born and raised in Oregon (Jarvinen et al. 2014), which may suggest a wider distribution than originally thought or a nematode spreading its distribution. L. chavezi infection is typically found in young, 2-3-year-old camelids, but clinical signs are generally rare. Lesions are associated with L3 and L4 enterohepatic larval migration, where the intestinal lesions are characterized by catarrhal and hemorrhagic enteritis with mucosal necrosis and the hepatic lesions by congestion, small foci of coagulative necrosis with mineralizing granulomas, and petechial hemorrhage (Jarvinen et al. 2014).
Interestingly, in one of the sections of brain, one of the mineralizing granulomas included a single transverse section of an approximately 130 µm diameter degenerate nematode with musculature resembling polymyarian-coelomyarian muscle and a smooth eosinophilic cuticle. As muscle is not a reliable identification feature, especially in degenerate nematode sections, the significance of this particular section is uncertain. However, it may indicate that the nematodes are all in fact a metastrongyle, possibly P. tenuis, or less likely, a dual infection of a trichostrongyle and metastrongyle. To further support the likelihood of this case representing a P. tenuis infection, a recent report describes a similar presentation of mineralizing granulomas in the neuroparenchyma of the spinal cord (von Stade et al. 2021).
Nakagun
1
247
NEVPC
2022
31
CANINE
Nasal cavities and brain: Nasal adenocarcinoma with cribriform invasion and multifocal meningeal metastases
The patient presented to the referring veterinarian for an onset of seizures in February 2021. Owner also reported reverse sneezing for years. The neurological and physical exam were both within normal limits. An MRI revealed an oval shaped mass in the right olfactory bulb/frontal lobe that was strongly contrast enhancing with significant perilesional edema. The cribriform plate was noted to be intact.
Options of medical management, radiation therapy and surgical debulking were discussed and the owner elected for surgical debulking (transfrontal craniotomy) and radiation therapy. Two separate surgeries were required to resect the majority of the tumor. Differentials of a meningioma vs. carcinoma were discussed and biopsy revealed a carcinoma.
The animal was treated with 20 fractions of Intensity-modulated radiation therapy (IMR) and continued to have several cluster seizures approximately every 7 weeks requiring extensive hospitalization.
A repeat MRI was done in July 2021, revealing an irregular contrast enhancing mass in the region of the cribriform plate along with multiple other new masses around the cerebral cortex.
The following week the animal was euthanized.
Nasal cavities and brain: Nasal adenocarcinoma with cribriform invasion and meningeal metastases
MARCINCZYK
1
248
NEVPC
2022
28
FELINE
1) Spinal cord (cervical region): Meningomyelitis, necrosuppurative, severe, focally extensive, subacute to chronic, with microabscesses, mononuclear perivascular cuffing, and intra-
2) Trigeminal motor nuclei: Wallerian degeneration, mild, multifocal
3) Trigeminal nerve roots: Neuritis, necrosuppurative, mild to moderate, bilateral, chronic, with mononuclear perivascular cuffing and Wallerian degeneration
11-year-old, male neutered, domestic shorthair cat
The cat presented to University of Georgia Veterinary Teaching Hospital neurology service for a 5-day history of a dropped jaw and inability to eat or drink. Bilateral trigeminal neuropathy was diagnosed on neurological examination. An atlantooccipital cerebrospinal fluid (CSF) analysis revealed a normal total white blood cell count, but an increased neutrophil percentage was identified on cytology. No infectious organisms or morphologic abnormalities were identified. The cat was treated with clindamycin and prednisolone. After two days, the cat’s jaw tone improved, and the cat was subsequently discharged. One week after discharge, the cat represented with tetraparesis. Neurological examination revealed a C6-T2 myelopathy with central cord syndrome and left lateralization. The neurologic signs progressed to absent sensation in the right thoracic limb. The cat eventually developed Horner syndrome and then became apneic. Euthanasia was elected approximately 20 hours after presentation.
On postmortem examination, no significant gross alterations were observed within the central nervous system or other examined tissues.
In contrast to humans and ruminants, listeriosis in carnivores is very uncommon. Experimental infections suggest domestic cats are highly resistant to Listeria infection1. In this cat, the pattern of lesions and clinical course suggest bacterial invasion of the CNS occurred via the trigeminal nerve. Potentially, the cervical spinal cord became affected through the nerve roots of the brachial plexus or caudal spread from the pons to the spinal cord. The infection source was not identified in this cat; it was fed a standard commercial diet and was kept indoors. Immunosuppression can play a key role in clinical listeriosis development in humans and few previous case reports of cats, though this is not a known predisposition in ruminants2,3. In the cat described, no underlying immunosuppression was identified. Listeriosis should be a differential diagnosis for feline infectious CNS disorders. Complete neuropathologic examination is vital to determine the prevalence of this disease in our domestic species.
REYES
1
249
NEVPC
2022
29
FELINE
Spinal oligodendroglioma, high-grade
12-year-old - Male castrated - Domestic longhair
This cat was presented for a one-week history of tail paralysis and paraparesis, as well as a one-month history of reduced jumping and climbing upon presentation. Within the past two weeks, two episodes of urinary obstruction were additionally reported. General physical examination abnormalities were limited to an overweight body condition (7 out of 9 on the Purina body condition scoring system). Neurologic examination revealed ambulatory paraparesis with marked plantigrade stance, reduced hopping in the pelvic limbs with normal paw placement, reduced extensor postural thrust, and reduced muscle tone in the pelvic limbs. Segmental reflexes were intact. The tail was paralyzed and flaccid with absent pain sensation. Pain was elicited on caudal lumbar spinal palpation. The patient’s neurolocalization was L4-S3. Radiographs of the lumbar spine taken four days prior to presentation were reportedly within normal limits, but a pre-operative MRI revealed a spinal mass at the level of the L5-S1 segment. Though surgical debulking was attempted, euthanasia was ultimately elected intra-operatively as the process appeared more infiltrative than initially determined based on the MRI, combined with a presumptive cryosection diagnosis of spinal lymphoma.
The spinal mass manifested as a markedly infiltrative, diffuse and irregularly bulging spinal thickening, imparting a dark red-to-brown discoloration to the spine starting from the caudal aspect of the body of L4 to the cranial aspect of S1, most severely distorting the L5-S1 segment. Upon serial sectioning of the mass, marked, indiscriminate neoplastic infiltration of both the grey and white matter occurred in the affected segments. Based on these findings and coupled with the cryosections results, an initial diagnosis of spinal lymphoma was made.
This case represents a unique clinical presentation and progression of a feline spinal oligodendroglioma with the longest survival time (163 days) currently reported for feline spinal oligodendrogliomas. Oligodendrogliomas are rare in cats and occur mostly within the brain with only infrequent reports describing a spinal cord location. Spinal glial tumors (e.g., oligodendroglioma, astrocytoma, ependymoma) in general have a low prevalence in cats with a rate of 9.4% of all spinal tumors, of which lymphoma is the most common. Earlier reports on feline spinal cord tumors support a predilection for spinal gliomas to form within the cervical segments, and a previous retrospective study of feline gliomas with seven oligodendroglial tumors indicated only one tumor located within the lumbar spinal cord segments L5-L7.
Nelissen
1
250
NEVPC
2022
8
CLOUDED LEOPARD
Brain, suprasellar third ventricle mass: Meningioma.
14-year-old male clouded leopard
This clouded leopard presented for dull mentation and whole-body twitching seizure-like activity. Neurology consultation detected a subtle right head tilt and slow, wide circling to the left. Clinical signs progressed despite treatment with steroids and antibiotics. Two separate intra-cranial, extra-axial masses were detected on MRI. The patient was euthanized due to poor prognosis.
Brain, suprasellar third ventricle mass: Meningioma.
SCOTT
1
251
NEVPC
2022
24
FISH
1. Brainstem, spinal cord, spinal nerve roots, skeletal muscle (epaxial): Myriad multifocal microsporidian spores (consistent with Pseudoloma neurophilia)
2. Intestine: Intramucosal adult nematode with intraluminal ova (consistent with Pseudocapillaria tomentosa)
Adult male zebrafish
Five sump (sentinel) fish from an embryology research colony at the University of North Carolina - Chapel Hill were sacrificed and submitted for necropsy and histology for infectious disease monitoring.
No obvious gross abnormalities were noted.
In this case, the histopathologic findings are consistent with Pseudoloma neurophilia infection of the brain, spinal cord, and skeletal muscle and Pseudocapillaria tomentosa infection of the intestine in a zebrafish.
Nagel
1
252
NEVPC
2022
19
FISH
Juvenile Lumpfish (Cyclopterus lumpus)
This animal was maintained in a private aquarium. The aquarist noted a facial injury which was not healing. The animal was found dead.
REINHARDT
1
253
NEVPC
2022
25
CAPRINE
Adult Alpine intact doe goat of unknown age
ALUCARD
1
254
NEVPC
2022
23
CANINE
Brain: marked subacute to chronic granulomatous to pyogranulomatous meningoencephalitis with myriad intralesional fungal yeast consistent with Cryptococcus spp.
4-year-old spayed female Labrador retriever
A 4-year-old spayed female Labrador retriever initially presented for vision loss, characterized by running into walls and lack of awareness of surroundings. Fundic examination at that time revealed bilateral foci of retinal separation. The dog was started on doxycycline, amlodipine, and a short tapering dose of prednisone with no apparent improvement in vision. About two weeks after the onset of clinical signs, she started to appear painful and became very lethargic. She developed severe ataxia, which rapidly progressed (within a few days) to non-ambulatory tetraparesis with delayed to absent conscious proprioception in all four limbs (left > right). Other abnormalities on neurologic exam included dull mentation, absent menace response OU, positional rotary nystagmus OU (fast phase to the left), and miosis OU with intact pupillary light reflex OU. While hospitalized in the clinic, she became hypertensive and progressively bradycardic, presumably in response to increased intracranial pressure (Cushing reflex). Due to the dog’s rapid clinical decline, humane euthanasia was elected.
The gross lesions of multifocal pale tan-white nodules and gelatinous masses and corresponding histologic lesions of granulomatous to pyogranulomatous inflammation with myriad intralesional fungal yeast in multiple organs (brain, eyes, nasal cavity, lung, heart, kidneys, and skeletal muscle) are consistent with systemic mycosis. Given the characteristic histologic appearance of the yeast with narrow-based budding and a variably thick clear capsule that stains positively with mucicarmine, disseminated cryptococcosis was diagnosed. Fungal culture of the brain and kidney resulted in 3+ growth of Cryptococcus neoformans, confirming this histologic diagnosis. The robust inflammation associated with the fungal yeast and the occasional intermediate-based budding and chain arrangement of the fungal yeast in this case are not common with cryptococcosis and may be suggestive of a capsular variant.
Rasche
1
255
NEVPC
2022
30
CANINE
1. Cavernous hemangioma (angioma)
2. Severe, locally extensive, acute vascular necrosis with ischemic necrosis, hemorrhage, and neutrophilic and lymphoplasmacytic perivascular inflammation
8.5-year-old spayed female Pit Bull-type dog
The patient presented to a primary veterinary hospital in August 2020 for a history of grand mal seizures. The initial diagnostic work-up included magnetic resonance imaging (MRI). The MRI showed a T1-weighted mass in the left prosencephalon, which was diagnosed as a glial tumor. Treatment with levetiracetam (Keppra) was initiated. The patient was referred to two different veterinary neurologists and at the second neurologist, the neurologic examination was within normal limits, and serologic fungal testing was negative. Additional diagnostics, including CSF tap and biopsy were declined and the patient was treated with prednisone, Keppra, and radiation therapy.
After a rapid clinical decline, the patient became obtunded in October 2020 and presented to a neurologist. The neurologic examination was remarkably abnormal, with vestibular ataxia, poor postural reactions, increased spinal reflexes, left head tilt, and positional rotary nystagmus with a fast phase to the right. The neuroanatomic localization suggested disease in the ascending reticular activating system (ARAS), left prosencephalon, and within the caudal fossa. An MRI was repeated. This imaging survey revealed a larger, fluid-filled mass with distinct cavitation. The left-sided neural parenchyma was expanded by fluid, causing shift and tentorial herniation. The owner elected euthanasia, and the brain was submitted for evaluation.
SMITH
1
256
NEVPC
2022
2
AVIAN
30 year old, female Timneh Grey Parrot
Tocco
1
259
NEVPC
2022
27
CANINE
Cerebrum: Severe, generalized, subacute-to-chronic periventricular white matter necrosis with hydrocephalus ex vacuo, vascular mineralization, glial precursor mineralization, and moderate microgliosis
7-day-old, male, Boer goat
The patient presented to the referring veterinarian with a history of spastic paraplegia that had been present since birth. The patient was treated with vitamin E/selenium, tulathromycin (macrolide antibiotic), and non-steroidal anti-inflammatory drugs. Given the lack of response to treatment, the patient was euthanized.
Cerebrum: Severe, locally extensive, subacute-to-chronic, bilaterally symmetric periventricular leukomalacia with hydrocephalus ex vacuo
The gross and histological findings of periventricular white matter necrosis (leukomalacia) when viewed in conjunction with the clinical history of spastic hindlimb paraplegia since birth, are consistent with a condition known as periventricular leukomalacia (PVL).
Champion
1
261
NEVPC
2022
9
CANINE
Subcutis, superficial to left inguinal lymph node: Lymphoma, large cell, extranodal, cutaneous T-cell, German shepherd dog, canine.
6 year old female spayed German shepherd
This 6 year old female spayed German shepherd dog initially presented to the Kuwait Veterinary Detachment on 17 October 2021 for an intake physical exam on arrival where three masses were noted located caudal to the left shoulder, over the right flank, and caudal to the left elbow. On 21 October 2021, the patient re-presented to the Kuwait Veterinary Detachment for an acute, markedly swollen left pelvic limb and a firm, multilobulated, nodular swelling was noted in the inguinal region (area of the femoral pulse) during the exam. On 02-03 November 2021, the patient presented for an acute, edematous swelling around the right eye. The patient was returned to the USA on 06 November 2021 due to the ongoing medical issues.
On 10 November 2021, the patient arrived at Fort Jackson, SC and underwent an intake physical exam and all previously noted masses and swellings had resolved. However, a firm, dual lobulated mass was noted within the left inguinal region with mild thickening of the subcutaneous tissue cranial to the firm swelling. Excisional biopsy was performed.
None
While in humans panniculitis-like large T cell lymphoma appears to follow a less aggressive biological behavior, it has not been characterized in veterinary species. The most recent literature suggests a more aggressive biological behavior in canines with two of five dogs being euthanized within 16 and 17 days post-diagnosis due to disease progression and one dog (after receiving chemotherapy) being euthanized 7 months post diagnosis due to disease progression. This patient was euthanized 24 days after diagnosis due to progressive disease and widespread metastasis.
KUIPERS
1
263
NEVPC
2022
10
CANINE
Histopathologic findings:
Spinal cord: At the level of the T13-L1 segment, effacing the white matter and compressing the grey matter was a non-encapsulated, well-demarcated, expansile, mildly infiltrative, moderately cellular neoplasm composed of two distinct neoplastic cell populations. The first cellular population was an epithelial proliferation arranged in tubules, acini, and large cystic structures lined by either cuboidal, low columnar, or pseudostratified epithelium, with squamous metaplasia up to four-cells thick. Cystic spaces often contained mild amounts of eosinophilic to amphophilic cellular debris and sloughed epithelial cells. The second cellular population was a mesenchymal proliferation composed of spindle cells arranged in loose streams and occasional whorls. The spindle cells had indistinct cell borders, round to ovoid nuclei with a single nucleolus and finely stippled chromatin. Large areas of the adjacent neuroparenchyma were rarefied or had extensive necrosis and degeneration, with infiltration by numerous degenerative and intact neutrophils. Throughout the section were abundant dilated myelin sheaths that often contained either swollen eosinophilic axons (spheroids) or fragments of eosinophilic necrotic cellular debris (ellipsoids) and/or one or more Gitter cells (digestion chambers). The central canal was prominently ectatic in spinal cord sections caudal to the mass.
Histopathologic Diagnoses:
Spinal cord, T13-L1:
a. Ectopic (extrarenal) intradural nephroblastoma
b. Marked multifocal axonal degeneration with dilated myelin sheaths, spheroids, and ellipsoids
17 month old Cane corso dog
A 17-month-old, intact male, Cane Corso dog was referred to the Small Animal Emergency at the North Carolina State University for evaluation of a 10-day history of right hindlimb lameness with left hindlimb weakness. Neurologic examination was consistent with T3-L3 myelopathy, with thoracolumbar pain on palpation, conscious proprioception absent in the hindlimbs, withdrawal intact in all four limbs, and good anal tone; however, deep pain was subsequently deemed equivocal in the hindlimbs. Spinal radiographs showed no evidence of discospondylitis, disc disease, lytic changes, or vertebral fractures. Due to progressive clinical deterioration, humane euthanasia was elected.
Gross findings:
Spinal cord: At the level of T13-L1, there was a bulging, intradural, mottled white, dark red, and light brown, 1.5 x 0.9 x 0.9 cm mass that infiltrated the associated spinal cord on cut surface.
Gross diagnosis:
Spinal cord, T13-L1: intradural mass
Discussion:
The gross and histopathologic findings were most consistent with ectopic (extrarenal) nephroblastoma. While rarely reported in dogs, it is predominantly found in young animals, such as in this case. Ectopic nephroblastomas correspond to approximately 1% of all primary neoplasms in the central nervous system in dogs, particularly with lesions localizing to the caudal thoracic and lumbar spine (T9-L3).
Although the definitive pathogenesis is still unclear, it is believed that nephroblastomas arise from metanephric blastema. Histologic features typically consist of three distinct cell populations (epithelial, mesenchymal, and blastemal), and characteristic formation of acini, tubules, and structures reminiscent of fetal glomeruli are often seen. Nephroblastomas are immunoreactive to Wilm’s Tumor Factor 1 (WT-1), vimentin, and cytokeratin 19 (CK19); with WT-1 being considered pathognomonic for ectopic nephroblastoma in the spinal cord. The neoplasm, in this case, had two distinct cell populations, epithelial and mesenchymal. Distinct blastemal elements were not identified in the examined sections. Blastema can have an early epithelial or spindle appearance and may be histologically difficult to distinguish from the other two populations. Interestingly, a population with squamous metaplasia was also present, which has been described in human and veterinary nephroblastoma cases and is considered to be on the continuum of metanephric differentiation.
Renal nephroblastomas may have metastasis in up to 75% of the cases. Metastasis and/or secondary sites of ectopic nephroblastoma have been reported in dogs affecting the spinal cord segment along the L4-L6. In the case herein, an extensive number of additional tissues were also examined histologically, and no other sites had neoplastic involvement, ruling out primary renal nephroblastoma with metastasis. The neoplasm along with the associated axonal degeneration of the spinal cord correlates with the clinical presentation of progressive ataxia to bilateral paresis with proprioceptive deficits.
References:
1. Brewer DM, Cerda-Gonzalez S, et al. Spinal cord nephroblastoma in dogs: 11 cases (1985-2007). 2011; J Am Vet Med Assoc 238(5): 618–624.
2. Higgins RJ, Bollen AW, et al. Tumors of the Nervous System. In: Meuten DJ, ed. Tumors in Domestic Animals. 5th ed. Ames, IA: Wiley-Blackwell. 2017; 836, 863-864.
3. Meuten DJ, Meuten TJ. Tumors of the Urinary System. In: Meuten DJ, ed. Tumors in Domestic Animals. 5th ed. Ames, IA: Wiley-Blackwell. 2017; 646-647.
4. Pearson GR, Gregory SP, Charles A.K. Immunohistochemical demonstration of Wilms tumour gene product WT1 in a canine “neuroepithelioma” providing evidence for its classification as an extrarenal nephroblastoma. 1997; J Comp Pathol 116:321–327.
5. Popov SD, Sebire NJ, Vujanic GM. Wilms’ Tumour – Histology and Differential Diagnosis. In: van den Heuvel-Eibrink MM, ed. Wilms Tumor [Internet]. Brisbane, AU: Codon Publications. 2016; Chapter 1. Available from: https://www.ncbi.nlm.nih.gov/books/NBK373364/doi: 10.15586/codon.wt.2016.ch1
6. Vandevelde M, Higgins R, Oevermann A. Veterinary Neuropathology: Essentials of Theory and Practice. Hoboken: John Wiley and Sons. 2012; 153-154.
7. Vasei M, Moch H, Mousavi A, Kajbafzadeh AM, Sauter G. Immunohistochemical profiling of Wilms tumor: a tissue microarray study. 2008; Appl Immunohistochem Mol Morphol. 16(2):128-134. doi:10.1097/PAI.0b013e31804d6825
FEUTSCH
1
264
NEVPC
2022
4
REPTILE
Metastatic melanophoroma.
1-year-old, female
The patient was humanely euthanized following the regrowth of a previously removed melanophoroma on the inner thigh.
Metastatic melanophoroma.
SWAN
1
265
NEVPC
2022
6
SEAL
Brain (cerebellum): Expanding out from the white-gray matter junction, approximately 50% of the examined cerebellum is effaced by large, coalescing regions of central lytic necrosis and angiocentric hemorrhage surrounded by marked granulomatous inflammation with myriad intralesional fungal hyphae. Fungal hyphae are 5-15 µm wide and characterized by non-parallel, deeply eosinophilic cell walls with occasional septation, bulbous dilations and non-dichotomous branching. In areas of lytic necrosis, fungal hyphae are scattered among the cellular debris and are observed within necrotic vessels along with fibrin thrombi. In areas of granulomatous inflammation, hyphae are frequently surrounded or engulfed by multinucleated giant cells with up to 40 nuclei per cell as well as dense aggregates of eosinophils, lymphocytes, plasma cells, neutrophils, and macrophages. Rarely, discrete aggregates of deeply eosinophilic material surrounded by giant cells are also observed. Many small vessels within the areas of inflammation, particularly at the peripheral edge, are disrupted by a combination of fungal hyphae and mixed inflammatory cells with fibrinoid vascular necrosis and occasional thrombosis. Low numbers of similarly affected vessels as well as scattered multinucleated giant cells or inflammation with fungal elements are present within the surrounding neuropil along with mild to moderate gliosis, spongiosis, and perivascular cuffing by lymphocytes, macrophages and fewer eosinophils. There is mild to marked, lymphohistiocytic and eosinophilic meningitis which increases in severity when adjacent to the areas of affected neuropil, multifocally merging with the underlying inflammation.
Similar, less extensive lesions are present in the other regions of the brain (midbrain, thalamus, and pons). Within the cerebrum, inflammation is restricted to the meninges which are moderately expanded by edema, hemorrhage, lymphocytes, plasma cells and rare eosinophils.
Special Stains: Gomori’s Methenamine Silver Stain (GMS) and Periodic Acid-Schiff Stain (PAS) are applied to sections of brain with adequate positive and negative controls. Fungal hyphae stain positive with both GMS and PAS.
Morphologic Diagnosis:
1. Brain (cerebellum, brainstem, and midbrain): Severe subacute multifocal to coalescing necrohemorrhagic granulomatous and eosinophilic encephalitis with vasculitis, vascular necrosis, thrombosis, and myriad intralesional fungal hyphae consistent with mucormycosis
2. Brain (cerebrum, cerebellum, brainstem, and midbrain): Mild to marked subacute multifocal lymphohistiocytic and eosinophilic encephalitis
Additional Diagnoses:
Lung: Chronic focal granulomatous pneumonia with fibrinoid vascular necrosis, fibrin thrombi, and myriad intralesional fungal hyphae consistent with mucormycosis
External ear canals: Bilateral chronic lymphoplasmacytic otitis externa with mild fibrosis and intrafollicular mixed bacteria
Tracheobronchial, right axillary, and mesenteric lymph nodes: Mild to moderate follicular and paracortical hyperplasia with sinus histiocytosis (consistent with reactive lymph node)
14-year-old male harbor seal
A 14-year-old male harbor seal presented with rotary nystagmus, involuntary head movement, and a mild right head tilt. The animal also developed mild intermittent facial swelling, specifically under/around the eyes. The animal was started on enrofloxacin and meloxicam for possible otitis interna or bacterial meningitis, ponazuril for possible Sarcocystis neurona or Toxoplasma gondii, and given a B complex injection with 100mg thiamine for possible thiamine deficiency. Two days later, the animal developed right-sided Horner’s syndrome, difficulty chewing on the right side of the mouth, a left-sided white aural discharge, and paresis of the right forelimb. The animal was sedated for blood collection (CBC/Chemistry panel unremarkable). Following sedation, the animal remained minimally responsive for a prolonged period of time and was found deceased the following morning.
Brain: A 10 x 15 x 6 mm, moderately well demarcated region of the right dorsal cerebellum was discolored grey to faintly yellow. Similar, smaller foci were observed within the ventral right cerebellum, midbrain, thalamus and pons.
Respiratory system: The medial aspect of the right caudal lung lobe next to the right mainstem bronchus was effaced by a 5 x 5 x 6.5 cm, irregularly round, well demarcated, firm, beige mass.
Lymph nodes: The lymph nodes were moderately to markedly enlarged (right axillary, tracheobronchial, bilateral inguinal).
Ophthalmic system: There were bilateral mature cataracts.
Auditory system: The ear canals were dark gray with a slight granular texture; the tympanic bullae were filled with tan/pink material.
The ante-mortem clinical signs and cause of death in this animal were attributable to severe fungal infection of the brain associated with vascular compromise from vasculitis and thrombosis with subsequent hemorrhage and necrosis (infarction) predominately affecting the cerebellum, brainstem, and midbrain. Histologically identical fungal hyphae are observed within a fibrotic granuloma in the lung adjacent to a mainstem bronchus. Given the chronicity of the lung lesion, an initial respiratory infection with subsequent hematogenous spread to the brain is suspected. The morphology of the fungal hyphae and angioinvasion is most consistent with mucormycosis. Initial panfungal PCR designed to isolate zygomycetes failed to detect fungal DNA within the submitted sample, possibly due to prolonged fixation in formalin, however, further testing is being pursued.
Zygomycetes are saprophytic, non-contagious, filamentous fungi within the class of Zygomycetes which consists of orders Mucorales and Entomophthorales. The order Entomophthorales most commonly causes subcutaneous disease in immunocompetent hosts and includes the Basidiobolus and Conidiobolis genera. Order Mucorales most commonly causes angioinvasive systemic disease with subsequent tissue ischemia (mucormycosis) in immunocompromised individuals and includes the Absidia, Mucor, Rhizopus, Rhizomucor, and Mortierella genera. In humans, most cases are caused by fungi within the order Mucorales, and therefore the terms “mucormycosis” and “zygomycoses,” as well as "phycomycosis," are often use interchangeably.
Zygomycetes fungi are ubiquitous in the soil and decaying vegetation and basidioboli species have been isolated in the gastrointestinal tracts of amphibians, reptiles and macropods. Histologically, these fungi are distinguished by non-parallel, frequently wide, thick walls with infrequent septation and accompanied by granulomatous and eosinophilic inflammation. Three syndromes have previously been described in veterinary medicine including cutaneous/subcutaneous disease, most commonly in horses, rhinocerebral disease, and systemic disease with the pulmonary and gastrointestinal tract most affected. Six classifications are described in human medicine based on further anatomic localization: rhinocerebral, pulmonary, cutaneous, gastrointestinal, disseminated, and uncommon. The portal of entry is typically through cutaneous wounds, the respiratory tract, or the oral cavity with hematogenous systemic dissemination due to angioinvasion by the fungi. Zygomycosis in pinnipeds has been previously described in several case reports. The specific combination of lung and cerebellar infection with similar histologic lesions due to Rhizomucor pusillus has been reported in a ringed seal (Pusa hispida); as with the case described here, no predisposing condition was identified.
References:
Caswell JL, Williams KJ. 2016. Infectious diseases of the respiratory system. ln: Maxie MG,ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol 2. 6th ed. Philadelphia, PA: Elsevier Saunders. 573.
Ibrahim AS, Spellberg B, Walsh TJ, Kontoyiannis DP. 2012. Pathogenesis of mucormycosis. Clin Infect Dis. 54 Suppl 1(Suppl 1):S16-22.
Jacobsen ID. 2019. Animal Models to Study Mucormycosis. J Fungi (Basel). 5(2):27.
Kaplan W, Gross LJ, Ajello L, Ivens MS. 1960. Pulmonary mucormycosis in a harp seal caused by Mucor pusillus. Mycopathol Mycol Appl. 12:101-110.
Nakagun S, Okazaki M, Toyotome T, Sugiyama N, Watanabe K, Horiuchi N, Kobayashi Y. 2018. Fatal Pulmonary and Cerebellar Zygomycosis due to Rhizomucor pusillus in a Ringed Seal (Pusa hispida). Mycopathologia. 183(6):979-985.
Petrikkos G, Skiada A, Lortholary O, Roilides E, Walsh TJ, Kontoyiannis DP. 2012. Epidemiology and clinical manifestations of mucormycosis. Clin Infect Dis. 54 Suppl 1:S23-34.
Taboada J. Zygomycosis. 2020. IN: The Merk Veterinary Manual, online edition, Whitehouse Station, NJ:Merck & Co., Inc.
Vitosevic K et al. 2018. Effect of formalin fixation on PCR amplification of DNA isolated from healthy autopsy tissues. Acta Histochem. 120(8):780-788.
Acknowledgments: We would like to thank the North Carolina Zoological Park and associated veterinary staff, the Illinois College of Veterinary Medicine Veterinary Diagnostic Laboratory, as well as the NC State University College of Veterinary Medicine Histology Laboratory.
Womble
1
267
NEVPC
2022
22
AVIAN
1. Brain: Multifocal to coalescing granulomas with abundant intracellular acid-fast bacilli.
2. Spleen: Multifocal to coalescing granulomas with abundant intracellular acid-fast bacilli and suspect amyloid deposition.
3. Lung: Multifocal to coalescing granulomas with abundant intracellular and extracellular acid-fast bacilli.
4. Liver: Hepatitis, multifocal, granulomatous, with rare intracellular acid-fast bacteria and suspect amyloid deposition.
5. Thymus: Focal granuloma.
6. Coelomic fat: Steatitis, granulomatous, multifocal, moderate, with marked fat atrophy.
7. Small intestine: Enteritis, lymphoplasmacytic, mild to moderate.
8. Ventriculus: Degradation of the koilin layer and bacterial overgrowth.
2 y.o. female
Previously healthy adult redhead hen with a 3-week history of waxing and waning neurologic signs including: diminished reactivity to handling, intermittent nystagmus, head tremors, right-sided head tilt and tilt, depression. Leukocytosis with mature heterophilia, persistent despite ceftiofur, meloxicam, B-vitamins, itraconizol, and fluids. Splenomegaly noted on radiographs. Negative for and vaccinated against West Nile virus.
Rallied briefly followed by abrupt decompensation exhibiting: obtundity, opposing nystagmus (vertical in one eye and horizontal in the other), open mouth breathing, dorsal recumbency, mucous membrane pallor, and pyrexia.
Euthanasia elected due to progressive neurologic disease.
Clinical signs are attributed to granulomas in multiple locations, particularly the brain, due to
infection with acid fast bacteria. The bacterium in question has been confirmed by PCR to be a Mycobacterium sp.,
and M. avium complex is the most common source of mycobacterial disease in birds. This pathogen is a ubiquitous environmental microbe and extremely common as a cause of infectious disease in bird collections.
Amyloidosis, suspected in the spleen and liver, is a frequent sequela to mycobacteriosis in ducks due to the chronic inflammation induced by the bacterium.
HOLDER
1
270
NEVPC
2022
18
EQUINE
Histopathologic findings, left retrobulbar mass (provided scanned slide): Effacing and invading the ethmoid turbinates is a nonencapsulated, well-demarcated, moderately cellular neoplasm composed of poorly defined polygonal cells arranged in nests and packets within a delicate fibrovascular stroma. The cells have a moderate amount of pale eosinophilic, granular, cytoplasm, and a round to oval nucleus with finely stippled chromatin and 1-2 small nucleoli. Anisocytosis and anisokaryosis are mild. Two mitotic figures are present in ten standardized 400 fields (2.37-mm2).
18-year-old American Quarter horse gelding.
The patient presented to Comparative Ophthalmology at Auburn University of College of Veterinary Medicine in July 2021 with swelling and epiphora of the left eye for the past two weeks. Clinical examination revealed exophthalmos in the left eye with chemosis and periorbital swelling. The head CT showed an approximately 4.5-cm diameter mass in the left retrobulbar space with attenuation similar to soft tissue. The mass extended into the ethmoid turbinates and eroded the left aspect of the cribriform plate. Euthanasia was elected due to the poor prognosis.
The left eye was markedly enlarged and bulged from the orbit. An approximately 4-cm x 5-cm x 4.5-cm well-demarcated, multinodular, tan, and firm mass was present in the left retrobulbar space. The neoplasm compressed the left eyeball, invaded the left medial orbital wall, and infiltrated and effaced the medial aspect of the left ethmoid turbinates. The mass was tan and multilobulated on the cut surface.
Literature review of causes in equine exophthalmos in orbit include neoplasia, inflammation, dermoid cyst, andIntradiploic hematoma. Orbital (extra-adrenal) paragangliomas are rare neuroendocrine tumors. Paragangliomas arise from the neural crest cells and can occur within the sympathetic or parasympathetic ganglia in the body. The unique extra-adrenal paragangliomas in horses likely originate from the ciliary ganglion, located within the orbital muscle cone in the ventrolateral position adjacent to the optic nerve. Exophthalmos and the infiltration into the adjacent tissues are the main clinical and pathological manifestations associated with orbital paragangliomas. In the present case, based on the clinical findings, computed tomography, and histopathological features, an orbital (extra-adrenal) paraganglioma was diagnosed.
YIN
1
403
Invertebrate Course
2022
15
HERMIT CRAB
about 6-year-old male hermit crab
The adult hermit crab was found dead without showing clinical signs. It had been kept for about 6 months in a community display tank of about 1500 gal at a temperature between 16-20¡C. It was fed fresh fish, mussels and silversides every other day. In the previous months no episodes of disease were found in the animals housed in the tank.
MAGI
1
404
Invertebrate Course
2022
3
BEE
1. Wings: Degeneration, diffuse, severe
2. Hypopharyngeal and Mandibular glands, head: Hypoplasia/atrophy, diffuse, severe, subacute to chronic
3. Eyes: Degeneration, multifocal, mild, chronic
Honeybee worker
Approximately 15,000 of 50,000 honeybee workers and drones in the colony were affected.
Shriveled wings
Protruding proboscis
MCHALE
1
405
Invertebrate Course
2022
6
ABALONE
1. Posterior-esophagus, intestine: Marked, multifocal, intra-epithelial bacterial colonies (consistent with WS-RLO and WS-RLOv)
2. Digestive gland: Severe, diffuse atrophy and loss with multifocal ductal metaplasia
3. Pedal muscle: Severe, diffuse, atrophy and loss
3-year-old, female
This animal comes from a recent study at Bodega Marine Laboratory analyzing age susceptibility to withering syndrome (WS). Half the animals, including this one, were exposed to WS agent. Since this study occurred after 2005, infection included withering syndrome Rickettsiales like organism variant (WS-RLOv) as well WS-RLO.
Shrunken (2/3 based on scoring system used at Bodega Marine Laboratory) foot.
Withering syndrome (WS) is a fatal disease of haliotids that has resulted in devastating population losses in multiple abalone species, including the endangered white and black abalone (Haliotis sorenseni and cracherodii). This disease was first recognized in 1985 and the etiologic agent, a marine Rickettsiales like organism (RLO) Candidatus Xenohaliotis californiensis (CaXc) was identified in 2000 (Friedman et al. 2000). White and black abalone are especially susceptible to infection, with up to 100% mortality in some studies (Crosson et al. 2014). More recently, beginning in 2005, WS-RLO variant (WS-RLOv) infections, which have their own distinct morphology, have increased in frequency. The etiology of the WS-RLOv is CaXc that has been infected with a phage hyperparasite (Friedman & Crosson 2012). Studies comparing WS-RLO and WS-RLOv infected black abalone, have shown that infection with the phage reduces the ability of CaXc to cause disease, demonstrating a fascinating example of evolved biological control (Friedman et al. 2014). This case represents a classic example of the pathogenic effects of WS-RLO infection and allow for comparison of the WS-RLO and RLOv morphology.
FINGERHOOD
1
406
Invertebrate Course
2022
16
SCORPION
1. Prosoma, dorsal body cavity: Hemocytic sarcoma
2. Mid-gut diverticula: Digestive gland atrophy, diffuse, severe, chronic
3. Cuticle: Erosion, multifocal, moderate, with melanization and fungal hyphae
4. Muscle: Myositis, multifocal to coalescing, moderate
5. Book lungs: Pneumonia, diffuse, mild
Greater than four-year-old, adult, male Asian jungle scorpion (Heterometrus sp.)
The animal was found deceased in its enclosure without antemortem clinical signs.
In this case, the bilateral, asymmetrical masses of hemocytes within the dorsal body cavity of the prosoma are composed of large numbers of monomorphic hemocytes with varying degrees of cytoplasmic granularity, anisocytosis, anisokaryosis, and multiple mitotic figures. There are no features of inflammation (e.g. melanization, encapsulation, elongation, degranulation, etc.). In addition, there are multifocal central areas of necrosis, which are not a feature of inflammation and are most suggestive of a neoplasm that has outgrown its blood supply. Based on these features, this is consistent with a hemocytic sarcoma.
This case illustrates an example of hemocytic sarcoma in a scorpion. Invertebrates are documented to be affected by numerous tumor types, including carapacial wall tumors, papillomas, carcinomas, adenocarcinomas, and the most described, disseminated hematogenous neoplasms. Disseminated hematogenous neoplasms have been described across 15 species of mollusk, white shrimp, and mutant strains of Drosophila. While recent research has demonstrated improved knowledge of neoplasia in invertebrates, there is still a lack of understanding in tumor biology, cell identification tools (immunohistochemistry), staging, classification, and treatment.
The myositis may have been secondary to regional trauma/compression to the apodemes and muscle from the neoplasm. There was a bacterial biofilm overlying pulmonary lamellae with pneumonia and a mild fungal infection of the cuticle with melanization. Both are likely secondary lesions due to depression of the immune system, potentially from neoplasia or advanced age. The diffuse digestive gland atrophy is indicative of negative energy balance, often observed secondary to chronic infection or illness (likely due to neoplasia in this case).
Gaudette
1
407
Invertebrate Course
2022
7
BUTTERFLY
Morphologic Diagnosis: Caterpillar, fifth instar: Coelomitis, hemocytic, diffuse, moderate with severe fat body atrophy, muscle degeneration and larva consistent with Tachinidae sp, monarch butterfly, Danus plexippus.
5th instar larva
History: Wild caterpillar presented dead. The animal had no premonitory signs and was previously bright, eating, and beginning to pupate. Once the caterpillar was on silk and in ÒJÓ formation it changed to a duller and darker color, lost its firm fleshy texture, and became visibly thin and moribund.
Discussion: Monarchs (Danaus plexippus) are a charismatic butterfly species that have recently caught public attention due to their decline in numbers causing enthusiasts to raise these caterpillars and plant their host plant in their gardens. Here we cover one of the many challenges monarch face during their development. The larva of tachinid flies within the family Tachinidae are one of the most common monarch parasitoids. They are from a large order of two winged flies that parasitize a wide range of host from butterflies to arachnids. Although there are at least seven species that have been recently documented to parasitize Danaus plexippus, the most common species found is Lespesia archippivora. The female fly deposits eggs on the surface of young instar caterpillars, the eggs hatch and tachinid larva burrow into the caterpillar. The fly larvae go through three larval stages within the coelom of the caterpillar and emerge as late stage larvae or pupae. Early stage larvae associate with host trachea and develop a respiratory funnel, which is thought to be of host origin. Within the third stage the larvae become free and will devour most of the hostÕs innards.^
The third stage larvae or pupae emerge when the caterpillar is either in the ÒJÓ formation just about to pupate (as a 5th instar) or an early stage pupa. One caterpillar can have up to ten fly larva within their coelom. As seen in this case, these parasitoids causes extreme emaciation within their hosts but incite minimal inflammation with most of the inflammation being attributed to necrotic host tissue rather than the parasitoid itself.
Argue
1
408
Invertebrate Course
2022
12
FISH
1. Digestive gland: Marked, multifocal to coalescing, granulomatous adenitis with intralesional coccobacilli; Gland degeneration and atrophy
2. Gills: Mild, multifocal, acute granulocytic branchitis with mild coccidiosis (Aggregata sp., presumed)
3. Vascular channels: Minimal, multifocal granulocytic vasculitis with mild coccidiosis
4. Systemic heart: Mild, focal endocardial pigment accumulation
5. Coelom: Mild to moderate, multifocal serositis (coelomitis)
several months old, undetermined sex
The specimen was from a group of stumpy cuttlefish that had arrived at the Brookfield Zoo between late September and early October of 2021 as presumed juveniles. Intermittent deaths had been occurring in this group and this specific individual was found deceased in December 2021. It was suspected that the deaths within this population had been associated with reaching maturity and or senescence. No intraspecific aggression was witnessed.
No significant gross findings.
Cause of death was most likely due to extensive and chronic inflammation of the digestive gland with intralesional bacteria and possible degenerate coccidia. While bacteria were not noted in cells or vessels elsewhere, terminal bacteremia/septicemia was suspected given the vasculitis and mild coelomitis. The coccidia noted in the gills and vascular channels were morphologically consistent with Aggregata sp. Coccidiosis caused by Aggregata sp. (phylum Apicomplexa, family Aggregatidae) is a common gastrointestinal disease of benthic cephalopods worldwide and has been described in octopus, cuttlefish, and squid.1,2 Although coccidiosis is generally not considered fatal, it predisposes to secondary infections due to mucosal compromise and suppression of hostÕs innate immunity.2 In this individual, the presence of coccidia in the gills and other vessels indicated dissemination, which may have predisposed to bacterial infection. Although the examined sections did not show substantial gastrointestinal tract injury or compromise, the presence of disseminated coccidia indicated previous GI tract infection. Furthermore, it is highly possible that a lesion in the GI tract was excluded from examined sections.
PUSHINSKY
1
409
Invertebrate Course
2022
9
MILLIPEDE
Severe, regional, necrotizing and hemocytic myositis, coelomitis, and dermatitis with intralesional fungi and mixed bacteria
This individual was found deceased in its enclosure on top of the substrate.
White material was protruding from between two body rings. Placed in formalin for histopathologic analysis.
COOK
1
410
Invertebrate Course
2022
8
COCKROACH
2-year-old, male
This 2-year-old, male Madagascar hissing cockroach (Gromphadorhina portentosa) was found dead. There are 13 adult hissing cockroaches that reside in an exhibit enclosure. The exhibit measures 14"x7"x15". It is made of plastic and frosted on the back wall, black on the side walls, and clear on the front wall to allow guests to see in. The top panel of the exhibit is primarily metal screen. The substrate for the enclosure is 1" of cypress mulch which is spot cleaned daily and replaced as needed. When substrate is removed, it is frozen for 72 hours or more. There are 4 pieces of cork bark in the exhibit that allow the roaches to hide and utilize the vertical space. A 43-watt incandescent bulb illuminates the exhibit and provides warmth. The exhibit temperature is 78 degrees and humidity is 50%. The exhibit is lightly misted each morning to help with humidity. There is a naturalistic looking water bowl that contains small rocks and water. The rocks are utilized so the roaches do not fall in and drown. There is also a naturalistic food dish containing wheat bran and fish flakes. Daily, the roaches are also offered greens and vegetables. The produce is replaced the next day if not eaten in its entirety.
Seasonal, mass die-off of Siliqua patula (Razor clams) on Kalaloch beach (Washington state).
Truncated age categories at one WA beach suggest that localized, pulsed mortality events are occurring after clams have recruited to coastal beaches. This mortality has led to extensive harvest closures at Kalaloch Beach, WA.
Multiple moribund clams
HAWTHORN
1
412
Invertebrate Course
2022
13
LOBSTER
Hepatopancreas: Necrosis, multifocal, random, moderate to severe with hemocytes and gram-negative bacteria
Young adult Caribbean spiny lobster, Panulirus argus
Increased fatalities in a local public aquarium. Mortalities spanned multiple tanks connected to the same life support system. There was an absence of clinical signs and postmortem decomposition limited investigations, so an arbitrary individual was euthanized and submitted immediately for diagnostics.
Gross and microscopic findings for multiple maladies present similarly in lobsters because of their limited ability to respond to disease and bodily damage. This lobster had significant multifocal necrosis of the hepatopancreas centered on gram-negative bacteria. Vibrio harveyi was cultured, identified initially by MALDI-TOF MS and then confirmed by MLSA, nanopore and Illumina sequencing. Vibrio spp. result in morbidity and mortality for many aquatic animals. V. harveyi is considered one of the most significant pathogens to cultured shrimp resulting in necrosis of the striated tail muscle, while several other Vibrio spp. are implicated in limp lobster disease and luminous vibriosis. Laser capture microdissection and genome analysis for virulence factors and anti-resistance elements are ongoing.
BENNETT
1
413
Invertebrate Course
2022
5
TARANTULA
1. Proximal midgut tube (prosoma) and sucking stomach: Severe, segmental, ulcerative gastroenteritis with perforation, melanization, and intralesional fungal hyphae and bacteria
2. Brain and peripheral nerves: Marked, diffuse, hemocytic encephalitis and neuritis with liquefactive necrosis and intralesional fungal hyphae and bacteria
3. Aorta and large hemolymphatic vessels: Marked, multifocal, hemocytic vasculitis with intramural fungal hyphae and intravascular bacteria
4. Skeletal muscle: Moderate, regionally extensive, monophasic myofiber degeneration and necrosis
5. Midgut diverticula: Mild, multifocal, erosive diverticulitis
Adult female Brazilian red and white tarantula (Nhandu chromatus)
The animal was found deceased in its enclosure without antemortem clinical signs.
N/A
This case illustrates the intimate anatomic association between the central nervous system, alimentary tract, and cardiovascular system in arachnids Ð and the collateral consequences that can come with lesions in one of these systems. In arachnids, the esophagus transverses through the brain prior to entry into the sucking stomach, which becomes the midgut tube caudal to the brain. The aorta and large vascular branches are parallel and immediately dorsal to the intestinal tract and are intimately associated with the peripheral nerves branching from the brain. Collectively, this arrangement indicates that severe injury to any of these systems could affect the others by local extension.
For the present case, we propose the following pathogenesis to explain lesions: segmental ulceration and perforation at the junction between the stomach and midgut tube _ release of ingesta, including presumed normal bacteria and fungal flora _ regional organism proliferation, hemocytic inflammation and melanization _ local spread to the adjacent brain _ vascular invasion through aorta _ septicemia and systemic inflammation.
The cause of perforation is not apparent in this case, but we speculate a few factors could be contributing. First, the perforation occurred at the junction between cuticle-lined and non-cuticle lined alimentary tract; it is possible that this site may be predisposed to injury or perforation by coarser ingesta due to differences in barrier strength and/or peristaltic dynamics. To this point, in a retrospective study on histologic lesions in arachnids (n=26), in addition to the current case, we identified another case of ulceration at this site with bacterial translocation, regional cavitary inflammation, and aortic vasculitis.
Second, given the extensive growth of fungal organisms, it is possible that there was a primary fungal infection of the sucking stomach/proximal midgut tube leading to perforation. In the aforementioned retrospective study, fungal infection of visceral organs was relatively common (n=6/26), and in all 6 cases the alimentary tract was involved. In the same study, yeast organisms were often seen in normal alimentary tract lumina, suggestive of normal alimentary flora. It is possible that these may opportunistically colonize injured tissue (i.e. a site of mucosal erosion/ulceration) in the form of hyphae. Future studies including fungal culture of alimentary lesions, in addition to characterizing the normal arachnid alimentary flora, would aid in elucidating pathogenesis of this case, as well as further our collective understanding of the role of fungal disease in arachnid health.
Schreeg
1
414
Invertebrate Course
2022
11
OCTOPUS
Arm and suckers: Severe, multifocal to coalescing, cutaneous coccidiosis
Adult, female, common Atlantic octopus (Octopus vulgaris)
This octopus was collected from the wild in the Florida Keys, USA and transported to an aquarium in California for public display in January 2022. No significant physical abnormalities were noted at the time of arrival. Within three weeks of accession, the octopusÕs movements appeared uncoordinated and somewhat spastic. There were irregularly shaped areas of skin pallor randomly distributed on multiple arms. No lesions were noted on the mantle. Numerous suckers appeared rigid and did not grasp normally. They were also pale in color and were standing erect away from their attachment to the arm. Despite these physical anomalies, the octopus continued to eat its diet of thawed, frozen grass shrimp, thawed frozen fish, and live feeder goldfish.
On day thirty-five, the octopus was sedated by gradually introducing 95% ethanol into its holding tank. The animal was adequately immobilized at a concentration of 2.5%. Multiple affected suckers were excised distal to transfixation sutures. An affected distal arm was similarly excised. The left gill arch was exteriorized from the mantle cavity and an excision biopsy collected. All specimens were preserved in NBF and submitted for histological examination. At the time of surgical biopsy, it was noted that the animal had laid a clutch of eggs in the den, and would likely be senescing gradually over the subsequent weeks to months.
The amputated distal arm did not exhibit any color differences at the time of collection due to the effects of the ethanol sedation; a normal finding. The integument was intact. Excised suckers were stiff and extended. The margins of the suckers curled inward to a slight degree. Excised gill filaments were normal in color and texture.
MURRAY
1
415
Invertebrate Course
2022
1
CORAL
brush coral (Acropora hyacinthus): Severe, multifocal, pan-epithelial necrosis with zooxanthellae degeneration and bleaching, endolithic algal overgrowth and tissue invasion, and endolithic sea spiders.
Coral colonies from the species Stylophora pistillata, Pocillopora damicornis, Acropora tenuis, Acropora hyacithus, and Acropora millepora.
A coral reef system at the Steinhart Aquarium experienced a population explosion of pycnogonid sea spiders (Arthropoda: Class Pycnogonida) with subsequent negative health effects on the corals species in the system. Biopsies of corals were sent to Zoetis Reference Labs to aid with diagnosis and then monitoring of corals during treatment.
Ailing colonies exhibited a general poor appearance: pallor due to expulsion or degeneration of the pigmented commensal zooxanthellae that live within coral tissue (ÒbleachingÓ), a general loss of polyps, and exposure of white skeleton that comes from a recession or complete loss of the epithelial tissue that covers it.
KROL
1
416
Invertebrate Course
2022
16
SCORPION
1. Prosoma, dorsal body cavity: Hemocytic sarcoma
2. Mid-gut diverticula: Digestive gland atrophy, diffuse, severe, chronic
3. Cuticle: Erosion, multifocal, moderate, with melanization and fungal hyphae
4. Muscle: Myositis, multifocal to coalescing, moderate
5. Book lungs: Pneumonia, diffuse, mild
Greater than four-year-old, adult, male Asian jungle scorpion (Heterometrus sp.)
The animal was found deceased in its enclosure without antemortem clinical signs.
In this case, the bilateral, asymmetrical masses of hemocytes within the dorsal body cavity of the prosoma are composed of large numbers of monomorphic hemocytes with varying degrees of cytoplasmic granularity, anisocytosis, anisokaryosis, and multiple mitotic figures. There are no features of inflammation (e.g. melanization, encapsulation, elongation, degranulation, etc.). In addition, there are multifocal central areas of necrosis, which are not a feature of inflammation and are most suggestive of a neoplasm that has outgrown its blood supply. Based on these features, this is consistent with a hemocytic sarcoma.
This case illustrates an example of hemocytic sarcoma in a scorpion. Invertebrates are documented to be affected by numerous tumor types, including carapacial wall tumors, papillomas, carcinomas, adenocarcinomas, and the most described, disseminated hematogenous neoplasms. Disseminated hematogenous neoplasms have been described across 15 species of mollusk, white shrimp, and mutant strains of Drosophila. While recent research has demonstrated improved knowledge of neoplasia in invertebrates, there is still a lack of understanding in tumor biology, cell identification tools (immunohistochemistry), staging, classification, and treatment.
The myositis may have been secondary to regional trauma/compression to the apodemes and muscle from the neoplasm. There was a bacterial biofilm overlying pulmonary lamellae with pneumonia and a mild fungal infection of the cuticle with melanization. Both are likely secondary lesions due to depression of the immune system, potentially from neoplasia or advanced age. The diffuse digestive gland atrophy is indicative of negative energy balance, often observed secondary to chronic infection or illness (likely due to neoplasia in this case).
Gaudette
1
417
Invertebrate Course
2022
14
INSECT
Densovirus
Superworm beetle larva
PESSIER
1
418
Invertebrate Course
2022
10
TARANTULA
a. Basal segment and fang arthrodial membrane: Dermatitis, regionally extensive, chronic, marked with melanization and hemocytic coagula
b. Muscle: Myositis, multifocal, chronic, moderate with atrophy, degeneration, and regeneration
Mexican Red-knee Tarantula
Presented for anorexia and lethargy. The left chelicera was non-mobile. The patient was found deceased 10 months later.
None.
HANDBERG
1
419
Invertebrate Course
2022
4
OCTOPUS
1. Renal Appendage: Tubular necrosis, multifocal, moderate with epithelial ulceration and intralesional nephrolith
2. Digestive Gland: Glandular atrophy and fibrosis, diffuse, chronic, severe
Giant Pacific octopus
In May 2019, this octopus laid eggs, developed a mantle abrasion, and became hyporexic (food intake decreased by 50%). For one year, the mantle abrasion slowly healed, but hyporexia persisted and worsened. In November 2020, the octopus became pale with loss of sucker grip, decreased interaction, cloudy eyes, and decreased body mass. At that time, food intake became minimal to none, and the decision was made to humanely euthanize the octopus.
The body was pale, the eyes were cloudy, and there was decreased body mass. Internal examination revealed that the kidneys had multiple crystalline deposits.
HUGHES
1
435
Davis-Thompson
2022
GUINEA PIG
Trichofolliculoma
5 year old guinea pig
Large alopecic nodule on the dorsum
Trichofolliculoma
H&E
Trichofolliculomas are the most common skin tumor of the guinea pig. These cystic neoplasm contain multiple sets of folliculosebaceous units with project into the central lumen, and there is rudimentary trichogenesis. Surgical excision appears complete and should be curative.
WILLIAMS
None attached
1
437
Davis-Thompson
2022
NHP - RHESUS
Kidney: Glomus tumor
7y 5m year old male rhesus macaque (Macaca mulatta).
This monkey received 6.5 Gray total body irradiation four and a half years prior to necropsy as part of a study examining the acute and chronic effects of irradiation.
H&E
Glomus tumors are rare, typically benign tumors arising from periendothelial modified smooth muscle cells which form the Sucquet-Hoyer canal, a structure that regulates temperature and blood flow in the subcutis, and are most commonly described in the fingers of women.
Glornus tumors are rarely reported in domestic species. One publication from 1984 described four glomus tumors in adult rhesus monkeys, which had received total body irradiation, however the radiation dose was not specified. 4 While the most common anatomic location in humans are the finger tips, malignant glomus tumors with metastases have been reported, including several humans who had either primary or metastatic renal lesions.
WILLIAMS
1. AI-Ahmadie HA; Yilmaz A, Olgac S, Reuter VE. Glomus tumor of the kidney: a report of 3 cases involving renal parenchyma and review of the literature. Am J Surg Patho/. 2007;31: 585-591.
2. Chou T, Pan SC, Shieh SJ, Lee JW, Chiu HY, Ho CL. Glomus Tumor: Twenty-Year Experience and Literature Review. Ann Plast Surg. 2016;76 Suppl 1: 535-40.
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