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
Severe, multifocal to coalescing, acute, fibrinonecrotizing, hemorrhagic, and heterophilic enteritis with crypt loss and vasculitis
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
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
Severe diffuse subacute necrotizing enteritis with crypt necrosis and marked lymphoid depletion and necrosis (parvovirus)
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.
COOK
1
166
AAZV
2021
12
SKUNK
Striped Skunk (Mephitis mephitis), adult, female
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.).
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
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
Segmental to circumferential necrotizing, lymphocytic, plasmacytic arteritis, renal artery; Multifocal, mild to moderate lymphocytic, plasmacytic interstitial nephritis and pyelitis; membranous glomerulopathy
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
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
Severe, chronic, multifocal to coalescing lymphohistiocytic and necrotizing myocarditis
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
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
Moderate to severe, acute, multifocal, necrotizing hepatitis
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
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
Severe vascular and myocardial necrosis, degeneration, and hemorrhage with intranuclear endothelial inclusion bodies, heart
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
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
Diffuse large B cell lymphoma, immunoblastic subtype, tracheobronchial lymph node
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
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
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
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
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
Necrosis and loss, transabdominal, segmental, with myriad intracoelomic fungal hyphae and conidia
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
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
Perkinsiosis, disseminated
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
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
Epidermitis, necroulcerative and granulocytic, chronic, multifocal to coalescing, moderate, with intralesional hyphae and arthroconidia, moderate epidermal hyperplasia, subepidermal clefting, and intracellular edema
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
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
Severe, regionally extensive, necrotizing hepatitis with multiple granulomas and intralesional fungal hyphae
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
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
Rhinitis, exudative and hyperplastic, granulocytic and lymphocytic, severe, with associated spiral-shaped bacteria (Helicobacter sp.)
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
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
Moderate heterophilic nephritis with intratubular myxozoan spores and multifocal tubular necrosis and mild chronic granulomatous tubulointerstitial nephritis with intralesional trematode eggs
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
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
Trichomonal ingluvitis and esophagitis, hyperplastic and necrotizing, generalized, marked, chronic
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
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
Severe, multifocal to coalescing, necrotizing hepatitis with intracytoplasmic hepatocellular, intraendothelial and intrahistiocytic hemoprotozoal schizonts and megaloschizonts
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.
