Antemortem Diagnosis and Successful Long-term Management of Disseminated Intracoelomic Xanthogranulomatous Disease in an Eclectus Parrot (Eclectus roratus).

A 12-year-old male eclectus parrot (Eclectus roratus) was referred for evaluation of coelomic distention. Computed tomography and blood work revealed coelomic effusion with free coelomic mineral-attenuating material and elevations in the bile acids and aspartate aminotransferase activity, respectively. Coelomic effusion was consistent with macrophagic inflammation with abundant intracellular lipids. Initial treatment with meloxicam resulted in minimal patient improvement. Disseminated xanthogranulomatous inflammation was suspected based on imaging and diagnostic laboratory results, which were consistent with those previously reported. Biopsy samples of liver tissue and intracoelomic masses confirmed this diagnosis. Treatment was initiated with prednisolone 1 mg/kg/d for 6 months, followed by 0.5 mg/kg/d for 3 months. Clinical improvement was assessed based on owner evaluation, plasma bile acid concentrations, and repeated computed tomographic scans. After 2 months of treatment, the owner reported improved behavior and appetite; this persisted throughout treatment and when the bird was reexamined 17 months following the cessation of steroid therapy. Bile acid concentrations were normal 10 months after the prednisolone therapy was discontinued. Diagnostic imaging showed minimal coelomic effusion 10 months after the last prednisolone dose was administered, with improved ventilation of the air sacs and static to improved dystrophic mineral foci. This report describes the antemortem diagnosis and treatment of disseminated coelomic xanthogranulomatous disease in a psittacine species, with an observed measurable therapeutic response.

Genetic trends in parrot Bornavirus: a clinical analysis.

Parrot Bornavirus (PaBV) has been reported to cause indigestion and other wasting symptoms such as weight loss and lethargy. The pathogenesis of PaBV has yet to be fully elucidated. This study reports PaBV infections in South Korea and suggests a trend in the genetic information gathered from clinical cases. A total of 487 birds with or without clinical symptoms were tested for bornavirus. Twelve of 361 asymptomatic birds tested positive for bornavirus, while 15 of 126 birds with various symptoms tested positive. A segment of approximately 1,540 bps including the N, X, P and M proteins were obtained from 23 of the positive strains and analyzed with other strains found on GenBank that had clinical information. PaBV was type 2 and 4 in South Korea, and certain amino acid sequences showed a difference between symptom presenting animals and asymptomatic animals in the X protein and P protein. When considering that some asymptomatic cases may have been latent infections at the time of examination, it is plausible these trends may grow stronger with time. Majority of PaBV was type 4 in South Korea. If these trends are confirmed, diagnosis of potentially pathogenic PaBVs in a clinical manner will be possible during the early stages of infection.

Systemic avian poxvirus infections associated with the B1 subclade of canarypox virus.

Avian poxvirus infections typically manifest as 2 forms: cutaneous ("dry") pox, characterized by proliferative nodules on the skin, and diphtheritic ("wet") pox, characterized by plaques of caseous exudate in the oropharynx and upper respiratory and gastrointestinal tracts. Systemic spread of virus to visceral organs beyond the skin and mucous membranes is rarely reported. Out of 151 cases diagnosed with avian poxvirus over a 20-year period at a zoological institution, 22 were characterized as having systemic involvement based on histopathology and molecular findings. Gross lesions in systemic cases included soft white nodules scattered throughout the liver, spleen, and kidneys. Two histopathologic patterns emerged: (1) widespread histiocytic inflammation in visceral organs with intrahistiocytic viral inclusions and (2) severe, localized dry or wet pox lesions with poxvirus-like inclusions within dermal and subepithelial histiocytes. In situ hybridization targeting the core P4b protein gene confirmed the presence of poxvirus DNA within histiocytes in both patterns. Polymerase chain reaction was performed targeting the reticuloendothelial virus long terminal repeat (REV LTR) flanking region and the core P4b protein gene. Sequences of the REV LTR flanking region from all systemic pox cases were identical to a previously described condorpox virus isolated from an Andean condor with systemic pox. Sequences of the core P4b protein gene from all systemic pox cases grouped into cluster 2 of the B1 subclade of canarypox viruses. Systemic involvement of avian poxvirus likely occurs as a result of infection with certain strain variations in combination with various possible host and environmental factors.

Postmortem Evaluation of Cardiac Valvular Disease in Bald Eagles (Haliaeetus leucocephalus) and a Golden Eagle (Aquila chrysaetos).

Limited data are available regarding cardiac diseases in birds of prey despite their prevalence in these avian species. Literature regarding valvular lesions in birds of prey is scarce and includes single reports of left atrioventricular valvular endocarditis in an adult, free-ranging, male bald eagle (Haliaeetus leucocephalus) and aortic valvular endocarditis in an adult, free-ranging, female red-tailed hawk (Buteo jamaicensis). The purpose of this study was to evaluate the prevalence, signalment, gross necropsy findings, and histologic lesions of valvular lesions in eagles. In this retrospective study, necropsy reports for 24 free-ranging and captive eagles were evaluated over a 15-year period (July 3, 2006-February 28, 2021). Six (25%; 95% confidence interval: 8.9-58.9) birds, 5 bald eagles and 1 golden eagle (Aquila chrysaetos), met the inclusion criteria. Five (83.3%) of the 6 birds had valvular degeneration, 2 (33.3%) had endocarditis, and Staphylococcus aureus was cultured from 1 (16.7%) of the endocarditis cases. The 6 eagles with valvular lesions were all captive adults. Four of the birds were female (66.7%), and the aortic and left atrioventricular valves were equally affected. Acute or chronic cerebral infarcts were present in all 6 birds. Valvular cardiac disease should be considered as a differential diagnosis in eagles exhibiting respiratory distress, neurologic signs, syncope, or in cases of sudden death.

Grey parrot (Psittacus erithacus) beak papillae and nerves identified using novel 2-D and 3-D imaging modalities.

OBJECTIVE: The avian beak is a complex organ containing bone, neurovascular tissue, and keratinized covering (rhamphotheca). Nerve-rich papillae extend through bone into rhamphotheca providing sensory input from the beak tip. Beak trimming is a common procedure in avian species and is used for corrective, cosmetic, and behavioral modification purposes. Yet, practitioners are not well versed in complete beak anatomy, and therefore, beak trimming often disregards neurovasculature, injuring the patient and hampering recovery. Here, using comprehensive anatomical description, we aim to provide recommendations on how to safely perform beak trimming without damaging underlying sensory papillae. ANIMALS: Here, we evaluated beaks of 2 deceased grey parrots (Psittacus erithacus). PROCEDURES: In one, we used a novel stain and microcomputed tomography to visualize papillae in the upper and lower beaks. In a second, we hand isolated the upper and lower beak dermal papillae and used high-resolution photography plus traditional paraffin histology. RESULTS: Papillae and their nerves were easily identified in these 2- and 3-dimensional approaches. This allowed us to determine the approximate lengths of papillae within the upper and lower beak. CLINICAL RELEVANCE: Based on these findings, the authors recommend lateral radiographs of the bird's head and beak to identify the location of the underlying bone relative to the overlying rhamphotheca before performing beak trims. Specifically in grey parrots, the authors recommend the upper and lower beak should not be trimmed closer than 8 to 10 mm from the underlying bone. Further work is needed to support these recommendations and provide guidelines for other species.

Massive hepatic trematodosis in 5 juvenile bald eagles.

Hepatic trematodosis by opisthorchiid flukes has been reported sporadically in North American fish-eating raptors. Bald eagles (Haliaeetus leucocephalus) infected by these flukes often have various degrees of granulomatous cholangitis, pericholangitis, necrosis of adjacent hepatocytes, and subsequent hepatic fibrosis. Species identification has been complicated by the inability to dissect intact specimens from liver tissue. Between 2007 and 2018, 5 juvenile bald eagles with massive hepatic trematodosis were identified at autopsy. Histologically, flukes were non-spinous. Parasitologic identification revealed ventral suckers (80-93 µm diameter), and uteri containing golden, operculated eggs (~25.0 × 12.0 µm). An unfixed frozen liver sample of one eagle was analyzed by PCR and DNA sequencing targeting the large subunit rRNA, ITS region, and cox1 genes of the parasite. The fluke DNA sequences shared 99.6%, 98.4%, and 87.0% similarity, respectively, with Erschoviorchis anuiensis, a newly described opisthorchiid species infecting the liver and pancreas of fish-eating birds in Europe and Asia. Infection by E. anuiensis is highly pathogenic in several piscivorous bird species. The clinical significance of trematodosis in our 5 cases is uncertain because all birds had comorbidities.

Heterotopic Ossification Bone Formation in the Frontal Bones of an African Grey Parrot (Psittacus erithacus).

A 5-year-old, male African grey parrot (Psittacus erithacus) was presented with multiple, slow-growing, firm, bilateral masses around the dorsal orbital rims. Computer tomographic imaging revealed mild, incomplete bridging bone formation on the rostrodorsal aspects of the head. A moderate amount of smooth bone formation was identified at the rostrodorsal aspect to the left orbit, with minimal associated soft tissue swelling. Surgical biopsies were collected from the masses and histopathological analysis of the most rostral right mass showed well-differentiated bone, surrounded by dense fibrous connective tissue. Scattered, well-differentiated osteocytes were present within the bone. No evidence of neoplastic changes or infectious agents were identified. The histopathological changes were consistent with metaplastic bone formation. History obtained from the owner revealed recent head trauma, which likely induced the cranial heterotopic ossification in the African grey parrot.

Bilateral Cubital Lymphoma and Mycobacteriosis in a Salmon-Crested Cockatoo (Cacatua moluccensis).

A 32-year-old male salmon-crested cockatoo (Cacatua moluccensis) was diagnosed by cytology with bilateral cubital lymphoma and mycobacteriosis. Polymerase chain reaction assay testing confirmed Mycobacterium genavense. This patient was subsequently humanely euthanized. Postmortem histopathology confirmed both diagnoses with findings of multicentric lymphoma, acid-fast bacilli, and severe degenerative changes in all synovial joints examined. Immunohistochemical staining for paired box protein 5 of the cubital mass was positive for a high percentage of B-cell lymphocytes, consistent with B-cell lymphoma. This unusual case of two major diseases presenting concurrently in one patient raises the question of whether the pathogenesis could have an interdependent relationship. Mycobacteriosis, severe degenerative joint changes, or both may have stimulated lymphocytes, eventually leading to lymphoma. Additional screening and monitoring for comorbidities may be advised if 1 of these diseases are diagnosed in companion avian species.

A retrospective study of pigeon herpesviral infection in domestic pigeons in California (1991-2014) and literature review.

We characterized naturally occurring pigeon herpesvirus (PiHV; Columbid alphaherpesvirus 1) infection in domestic pigeons in California. We retrieved and analyzed 62 pathology reports produced between 1991 and 2014 at the California Animal Health and Food Safety Laboratory System. In 56 of the cases, the diagnosis of PiHV infection was established based on histopathology, either alone (44 cases) or combined with virus isolation (VI; 8), transmission electron microscopy (TEM; 3), or PCR (1); in the remaining 6 cases, the diagnosis was established based on VI (5 cases) or TEM (1) alone. PiHV infection affected 1 system in 34, 2 in 16, and ≥3 systems in 6 cases; data were not available for the remaining 6 cases. Most commonly affected was the digestive system (55 cases), followed by the respiratory tract (5) and lymphoid system (2). The liver (39 cases), crop (17), and esophagus (14) were the organs affected most commonly. Many affected cells often bore single eosinophilic intranuclear inclusion bodies. PiHV infection was a secondary diagnosis or incidental finding in 35 cases. Most (55) cases had 1 (21), or up to 4 (34), other concurrent infections; the most common concurrent infections were pigeon circoviral infection (26), trichomonosis (24), aspergillosis (11), and colibacillosis (10).

Endogenous lipid pneumonia associated with atherosclerosis in a blue-fronted Amazon parrot (Amazona aestiva).

Endogenous lipid pneumonia is a rare inflammatory, non-infectious lung disease characterized by the accumulation of endogenous lipids in alveolar macrophages. It has been associated with bronchial obstruction, chronic lung inflammation, alveolar proteinosis and lipid storage disorders. A 14-year-old female blue-fronted Amazon parrot (Amazona aestiva) presented with intermittent dyspnoea, neurological signs and persistent lipaemia of unknown aetiology. At necropsy, the most relevant gross findings were increased rigidity of the great vessels, lungs with diffuse grey to whitish discolouration of the parenchyma and multifocal small yellowish nodules. Microscopic examination revealed typical lesions of atherosclerosis and severe multifocal accumulation of foamy macrophages filling the parabronchi, which led to a diagnosis of endogenous lipid pneumonia. Although the relationship between dyslipidaemia, atherosclerosis and endogenous lipid pneumonia in birds is not well established, the chronic dyslipidaemia of unknown origin could be involved in the pathogenesis of both the atherosclerosis and the endogenous lipid pneumonia. The present case highlights the need to better understand the relationships between various disorders of lipid metabolism in psittacine birds.

Intralesional application of ribavirin in two American flamingos (Phoenicopterus ruber) with poxvirus infection.

We report the successful treatment of poxvirus lesions in two juvenile American flamingos (Phoenicopterus ruber) with experimental low-dose intralesional ribavirin injection. In the first flamingo, the size and location of a beak verrucosity interfered with feeding, and after multiple surgical interventions, an experimental therapy of low-dose intralesional ribavirin was implemented with close blood parameter monitoring to minimize any potential side effects due to systemic antiviral administration. The second flamingo had a poxvirus lesion on the tibiotarsus, which recurred after unsuccessful conservative medical treatment and surgical intervention and a course of intralesional ribavirin therapy was implemented. Regression of the lesions in both flamingos commenced within 3 days of ribavirin treatment resulting in complete resolution within 6 weeks of onset of ribavirin treatment.

Undifferentiated Wing Sarcoma in a Peach-Faced Lovebird (Agapornis roseicollis).

A 10-year-old peach-faced lovebird (Agapornis roseicollis) was evaluated for an ulcerated and painful mass at the location of a fracture 2 years previously. Whole body radiographs showed a humeral fracture with a presumptive neoplastic proliferation in the distal diaphysis. Right wing amputation was elected but the animal died during recovery from surgery. Histopathological examination of the amputated wing revealed an infiltrative sarcomatous neoplastic proliferation. Immunohistochemistry (IHC) was carried out to characterize the tumour using antibodies against vimentin, desmin, smooth muscle actin (SMA), S-100, ionized calcium-binding adapter molecule-1 (IBA-1), CD18, cytokeratin and epithelial membrane antigen (EMA). The mesenchymal component of the mass was immunolabelled for vimentin and SMA and sparse epithelial cells were immunopositive for cytokeratin. Very few scattered cells were immunopositive for CD18 and IBA-1. The final diagnosis was consistent with an undifferentiated sarcoma with intralesional hyperplastic epithelium. According to the location, the history of a previous fracture and the histological pattern and IHC profile, the tumour was classified as an undifferentiated sarcoma with entrapped air sac epithelium.

Liposarcoma of Probable Medullary Bone Origin in a Lovebird (Agapornis roseicollis).

A 15-year-old female peach-faced lovebird (Agapornis roseicollis) was presented to the hospital for a possible left wing injury and an inability to fly after falling in its cage. On physical examination the left elbow was swollen and painful. Radiographic images revealed left wing soft tissue swelling surrounding the elbow and lysis of the distal humerus with extensive cortical thinning. Subsequent high-definition volumetric-imaging 3-dimensional computed tomography (HDVI 3D CT) revealed a pathological fracture, cortical lysis, periosteal reaction, and abnormal intraosseous soft tissue of the left humerus with associated soft tissue swelling, suggestive of neoplasia. No evidence of metastatic disease was identified. Surgical amputation of the left wing was elected. A liposarcoma and pathologic fracture of the humerus were diagnosed histologically and by oil red O staining for lipids in the neoplastic cells. The morphologic features of the tumor suggested that it developed within the adipocyte component of the medullary bone. The incision at the amputation site healed without complication. A follow-up HDVI 3D CT performed 4 months postsurgery showed no evidence of metastatic disease. To the authors' knowledge, this is the first report of a primary liposarcoma of medullary bone origin in an avian species.

Vasculitis Associated with Parrot Bornavirus 4 Infection in a Rose-Crowned Parakeet (Pyrrhurarhodocephala).

A 3-month-old, female rose-crowned parakeet (Pyrrhura rhodocephala) was found dead after a 24-h course of lethargy and passing blood-tinged faeces. Fine white streaks were seen in the pectoral muscles on necropsy. Microscopic examination revealed typical lesions of avian ganglioneuritis and vascular necrosis in the pectoral muscles, myocardium, kidneys, air sacs, adrenal glands, pancreas and thyroid gland. These lesions were characterized by mural fibrinoid necrosis of small and medium-calibre arteries and arterioles, associated with lymphoplasmacytic inflammation, necrosis, atrophy and fibrosis of the surrounding tissues. Parrot bornavirus (PaBV) nucleoprotein was demonstrated by immunohistochemistry in smooth muscle and endothelial cells of many vessels. An avian bornavirus was isolated from kidney tissue and its identity confirmed as PaBV-4 by sequencing and phylogenetic analysis. We postulate that the vascular lesions could have been immune-mediated and that PaBV-4 may have played a role in its pathogenesis.

Adenoviral infection in 5 red-tailed hawks and a broad-winged hawk.

Adenoviral infections among raptors are best described in falcons and are characterized most commonly by necrotizing hepatitis and splenitis; only one case has been reported in a hawk. Five red-tailed hawks (Buteo jamaicensis) and a broad-winged hawk (Buteo platypterus) had an adenoviral infection based on history, histopathology, negative-stain electron microscopy, and PCR. All birds had acute onset of illness resulting in death; 3 had evidence of a concurrent bacterial infection. Microscopically, all 6 birds had solitary, pale eosinophilic-to-amphophilic, intranuclear inclusion bodies within presumed hematopoietic cells in bone marrow and macrophages in spleen. Five of the 6 birds had similar inclusions within hepatocytes and Kupffer cells. All but one bird had severe bone marrow necrosis. There was moderate splenic necrosis (3 of 6) and mild-to-marked hepatic necrosis (4 of 6). Negative-stain electron microscopy demonstrated adenoviral particles in bone marrow (5 of 6), liver (1 of 5), and/or spleen (1 of 5). PCR was positive for adenovirus in bone marrow (3 of 5), liver (1 of 3), spleen (4 of 6), and/or intestinal contents (2 of 3). Viral DNA polymerase gene sequences clustered within the Siadenovirus genus. There was 99% nucleotide identity to one another and 90% nucleotide identity with the closest related adenovirus (Harris hawk, EU715130). Our case series expands on the limited knowledge of adenoviral infections in hawks. The splenic and hepatic necrosis, and particularly the hitherto unreported bone marrow necrosis, suggest that adenoviral infection is clinically relevant and potentially fatal in hawks.

RETROSPECTIVE REVIEW OF MORBIDITY AND MORTALITY IN A POPULATION OF CAPTIVE BUDGERIGARS (MELOPSITTACUS UNDULATES).

This retrospective study reviews the diseases associated with morbidity and mortality in 221 budgerigars (Melopsittacus undulates) from a captive population from 2013 to 2019. The study aimed to evaluate the health status of a flock of budgerigars typical of today's zoologic collections. Based on previous literature, it was hypothesized that age-related conditions such as neoplasia would be common, whereas metabolic and nutritional disorders would be less common. Neoplasia was widespread among the population, affecting 34% of birds (75/221). Carcinomas made up most neoplastic processes and most commonly affected the renal system (n = 22), followed by the proventriculus (n = 7). Pituitary, adrenal, and hepatocellular carcinomas were less commonly diagnosed. Sarcomas affected the population less often than carcinomas and were found within the coelom (undifferentiated four cases), within the spleen (three cases), within the kidney (two cases), and one subcutaneous soft tissue sarcoma. There were five cases of multicentric lymphoma found most commonly affecting the spleen and liver. Benign neoplasms affected the pituitary most commonly (nine cases), followed by the reproductive system, with seminomas (seven cases) being most common. Macrorhabdus ornithogaster (MO) was found in 56 cases. The majority (38 cases) were found in conjunction with a range of comorbidities, but several birds experienced MO infections alone, and it was thought to have been the cause of death in these birds (22 cases). In contrast to our hypothesis, disease associated with nutritional or metabolic disorders impacted a substantial portion of the population; hepatic lipidosis (26 cases) was the most common along with obesity (26 cases), followed by atherosclerosis, xanthomas, and gout (8, 7, and 4 cases, respectively). Traumatic lesions were noted in 41 cases and were most commonly characterized by head trauma and cerebral hemorrhage. Toxicity was rare; five total cases caused by a single carbon monoxide event were identified.

Unique Isospora-associated histologic lesions in white-rumped shama (Copsychus malabaricus).

Twenty-one white-rumped shamas (19 necropsied, 2 biopsied) (Copsychus malabaricus) housed at the San Diego Zoo between 1992 and 2020 were diagnosed with Isospora infection based on evaluation of histologic sections. Review of these cases revealed a consistent histologic lesion characterized by nodular aggregates of atypical epithelioid macrophages containing few intracytoplasmic protozoa, with or without lymphocytic infiltrates. Of the 19 necropsied cases, 16 (84%) had systemic lesions variably affecting the liver, spleen, gastrointestinal tract, lung, pancreas, connective tissues, or bone marrow, while all 21 diagnosed cases had skin involvement. The findings suggest that white-rumped shamas have a unique inflammatory response to isosporosis with a predilection for the skin. Skin may be a diagnostically sensitive sampling site for histologic diagnosis of Isospora in this species.

Fatal Sarcocystis calchasi-associated meningoencephalitis in 2 captive vulturine guineafowl.

Two captive vulturine guineafowl (Acryllium vulturinum) were presented with lethargy, hyporexia, weight loss, and progressive neurologic signs. One of the guineafowl was seropositive for Sarcocystis falcatula (1:50 dilution). Both guineafowl died within 5 d of presentation. Histologic examination revealed nonsuppurative meningoencephalitis with gliosis, associated with occasional schizonts in the neuropil. Using fresh-frozen brain tissue, PCR was performed to amplify the ITS1 RNA region and portions of the 18S ribosomal RNA gene (18S gene) and the 28S ribosomal RNA gene (28S gene). Analysis of nucleic acid sequences from the resulting amplicons indicated that Sarcocystis calchasi was the likely cause of disease. To our knowledge, S. calchasi-associated disease has not been reported previously in the order Galliformes.

Medullary bone in male budgerigars (Melopsittacus undulatus) with testicular neoplasms.

Medullary bone is a calcium-rich, labile bone normally occurring in female birds with each egg-laying cycle. The stimulus for formation of medullary bone is, in part, the cyclic increase in serum estrogens produced by preovulatory ovarian follicles. Increased bone density due to formation of medullary bone, particularly in pneumatic bones, has been termed polyostotic hyperostosis, even if physiologic. This study investigated the formation of medullary bone in nonpneumatic (femur) and pneumatic (humerus) bones in sexually mature male budgerigars submitted for autopsy. Of the 21 sexually mature male budgerigars submitted for autopsy, 7 (33%) had medullary bone in 1 or more bones examined. All 7 male budgerigars with medullary bone had a testicular neoplasm, which was morphologically consistent with a testicular sustentacular cell tumor, seminoma, or interstitial cell tumor. Medullary bone was not present in the 14 cases with other diseases. Medullary bone formation in pneumatic and nonpneumatic bones can occur in male budgerigars with testicular neoplasms. Radiographic increases in medullary bone density, particularly in the humerus, could provide antemortem indication of testicular neoplasia in male budgerigars.

Clinical and pathologic evaluation of chorioretinal lesions in wild owl species.

OBJECTIVE: Investigate histopathology and spectral-domain optical coherence tomography (OCT) imaging of wild owls with chorioretinitis and identify any potential correlation with an infectious etiology. MATERIALS AND METHODS: Ophthalmic examination and retinal OCT imaging were performed on fifteen great horned (Strix varia) and barred (Bubo virginianus) owls (30 eyes) with chorioretinitis and five owls with normal eyes (10 eyes). Testing to investigate the presence of potential infectious diseases included a complete blood count, biochemistry, protein electrophoresis, West Nile virus (WNV) plaque reduction neutralization test, Toxoplasma gondii modified direct agglutination test, WNV RT-PCR, and Avian Influenza RT-PCR. A necropsy was performed on all owls, including ocular histopathology. RESULTS: Fundus lesions included retinal detachment (7/15 owls), depigmented lesions (12/15), pigment clumping (8/15), and retinal tear (4/15). All birds were negative for WNV and Avian Influenza on RT-PCR. Of the owls with chorioretinitis, 3/15 were seropositive for WNV and 7/15 for T. gondii. Optical coherence tomography of 25/30 affected eyes revealed outer retinal lesions (19/25 eyes), retinal detachment (16/25), and retinal tears (3/25). Histopathological examination revealed outer nuclear layer atrophy (19/30 eyes), retinal detachment (18/30), retinal tears (7/30), suprachoroidal hemorrhage (12/30), scleral rupture (3/30), and ossicle fracture (3/30). CONCLUSIONS: Although 20% of birds were seropositive for WNV and 46.6% for T. gondii, histopathologic findings supported that the posterior segment lesions in the study group were likely due to blunt ocular trauma rather than an infectious etiology. The results of OCT imaging and histopathology documented retinal changes most consistent with blunt ocular trauma.