Conjunctival xanthoma in a blue and gold macaw (Ara ararauna)

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.

Avian Dermatology

Dermatologic conditions are common in avian practice and can be caused by a huge array of potential disorders, ranging from infectious diseases, ectoparasites, metabolic disorders, nutritional deficiencies, and management deficits. The skin is the largest organ in the body and has the potential to lead to significant discomfort and welfare compromise when pathology is present. Some conditions may be relatively pathognomonic based on gross findings, whereas others may require a full diagnostic workup to investigate. Getting to the bottom of skin lesions and disorders often involves identification and correction of the underlying cause, rather than just treating the lesions present in the integument.

Case Series of Disseminated Xanthogranulomatosis in Red-crowned Parakeets (Cyanoramphus novaezelandiae) with Detection of Psittacine Adenovirus 2 (PsAdV-2)

Simple Summary

Lipometabolic disorders, such as xanthogranulomatosis, are common diseases in avian medicine. Various manifestations of lipometabolic disorders and risk factors for acquiring lipometabolic diseases have been described in the past years. Xanthogranulomas are usually limited to the skin and supposed to be associated with traumatic or inflammatory injuries in that area. Disseminated xanthogranulomatosis, appearing simultaneously in several internal organs, has been recently described in psittacine birds, the cause of the diseases was not known. Here, we describe a case series of disseminated xanthogranulomatosis in another psittacine species, the Red-crowned Parakeet (Cyanoramphus novaezelandiae) and a possible association with a concurrent psittacine adenovirus 2 (PsAdV-2) infection. Viral infections that trigger lipometabolic diseases have been described in human medicine in some species of small animals and in chickens. PsAdV-2- infections are widely distributed in avian species. A possible association between PsAdV-2- infections and lipometabolic diseases in the Red-crowned Parakeet should be considered. Individual birds and flocks with both or either of these diseases should be carefully examined and monitored.

Abstract

Xanthogranulomatosis is a common dermatological disease in birds. This form of inflammation, possibly associated with lipometabolic disorders, can also be seen in visceral organs, which as yet has only rarely been described in avian medicine. In general, diseases related to impaired lipid metabolism are frequently reported in avian medicine, with hepatic steatosis and atherosclerosis being the most common. In human medicine, infectious agents—especially some strains of adenovirus—were implicated in contributing to lipometabolic disorders; this has also been described for chicken. Here, a case series of six Red-crowned Parakeets (Cyanoramphus novaezelandiae) is presented, all cases being characterized by psittacine adenovirus 2 (PsAdV-2) infection with or without disseminated xanthogranulomatosis. The affected individuals were examined alive by clinical examination. Total body radiographs were taken of two birds, haematology and blood biochemistry results were achieved in one bird. The birds either died immediately after clinical presentation or within two days, two individuals were euthanized due to worsening of their clinical condition. All birds underwent a post-mortem examination. While four birds were finally diagnosed with disseminated xanthogranulomatosis, all six individuals had large eosinophilic intranuclear inclusion bodies in the epithelial cells of the collecting ducts of the kidney and tested positive for PsAdV-2. Further examinations are needed to clarify to what extent PsAdV-2 might elicit lipometabolic disease in birds, or psittacines in general, and, in particular, the Red-crowned Parakeet.

HYPERLIPIDEMIA AND XANTHOMATOSIS IN YELLOW-FOOTED ROCK WALLABIES (PETROGALE XANTHOPUS) UNDER MANAGED CARE

Xanthomas are localized lipid deposits in organs with associated granulomatous inflammation. Xanthomatosis is a rare condition in both human and veterinary medicine and is often linked to inherited or acquired dyslipidemias. Three female yellow-footed rock wallabies (Petrogale xanthopus) at a single institution were diagnosed via biopsy with cutaneous xanthomas secondary to hypertriglyceridemia and hypercholesterolemia, and an additional two female yellow-footed rock wallabies were diagnosed with xanthomas at a second institution. All cases presented with cutaneous masses at the haired skin and paw pad junctions of the extremities, and/or mucocutaneous junctions of the face or urogenital tract. The clinically affected individuals were overconditioned or obese, had lipemic serum, and had elevations in blood cholesterol and triglyceride levels. When full lipid panels were performed, inverse high- and low-density lipoprotein fractions were observed. Six other individuals at the first institution had identical husbandry but were of more appropriate body condition, were normolipidemic, and had no xanthomas. One of the affected animals was also concurrently diagnosed with hepatic lipidosis via liver biopsy. Pedigree review and evaluation for underlying endocrine diseases such as hypothyroidism were performed. Because all affected animals were found to be related, a genetic predisposition is possible but requires further investigation. Consideration for the predisposition of some individuals for obesity, hyperlipidemia, and subsequent xanthoma formation should be factored in the husbandry and medical management of this species.

Disseminated coelomic xanthogranulomatosis in eclectus parrots (Eclectus roratus) and budgerigars (Melopsittacus undulatus)

Xanthogranulomatosis is an inflammatory lesion characterized by lipid-containing macrophages, extracellular lipid, hemorrhage, and necrosis. We describe disseminated intracoelomic xanthogranulomatosis in 5 eclectus parrots (Eclectus roratus) and 2 budgerigars (Melopsittacus undulatus). Postmortem, clinicopathologic, and historical case material was reviewed. Ages ranged from 3 to 24 years; there were 5 males and 2 females. Table food was included in the diet of 3/5 cases, and animal products were included in 2/3 cases. Common clinicopathologic abnormalities included leukocytosis (4/5 cases) and elevated concentrations of bile acids (3/4 cases) and cholesterol within 6 months prior to death (2/4 cases). At postmortem examination, all 7 birds had grossly visible, irregular, soft, tan to yellow, amorphous plaques distributed on the surfaces of the viscera and body wall. Histologic evaluation and oil red O stain revealed xanthogranulomatous inflammation with phagocytized and extracellular lipid, necrosis, cholesterol clefts, fibrosis, and mineralization. Infectious agents were not identified with special stains in all cases. Concurrent hepatobiliary disease was present in 6/7 cases, and 6/7 had lipid accumulation within the parenchyma of various visceral organs. Five cases had atherosclerosis of great vessels. We describe a unique form of disseminated coelomic xanthogranulomatosis in 2 psittacine species. This condition should be recognized as a differential diagnosis in cases of disseminated coelomic mass formation and coelomic distension in psittacine birds, particularly in eclectus parrots and budgerigars.

Liposarcoma in a Backyard Silkie and Retrospective Summary of Neoplasms Diagnosed in Backyard Chickens Submitted to the California Animal Health and Food Safety Laboratory System, 2008-2017

Liposarcomas are a malignant neoplasm of adipocytes, and are rarely diagnosed in avian species. This case report describes the evidence supporting a diagnosis of metastatic liposarcoma in a backyard silkie chicken. On September 28, 2017, a dead 3-yr-old backyard silkie chicken, with a history of unknown skin lesions involving the entire body and severe weight loss, was submitted to California Animal Health and Food Safety Laboratory System-Turlock branch for necropsy. At necropsy, raised necrotic lesions involving the majority of the skin and multiple nodules in the liver, spleen, and bone marrow were noticed. Microscopically, stellate, spindle, and myxoid cells containing large vacuoles, which were confirmed as lipid droplets by Oil Red O, were observed infiltrating the dermis and underlying a necrotic epidermis, with metastasis to liver, spleen, bone marrow, and ovary being the most significant findings. PAS, Oil Red O, Ziehl-Neelsen, Congo red, Gram, and Von Kossa stains, along with immunohistochemistry for pan cytokeratin, vimentin, S100, CD3, pp38, and Meq were used to classify the lesions. Intensely positive vimentin immunohistochemistry, along with large quantities of Oil Red O-positive lipid droplets within the neoplastic cells, were supportive of our diagnosis of liposarcoma. The incidence of neoplastic diseases diagnosed in backyard flock submissions to CAHFS system wide from 2008 to 2017 was also reviewed.

A clinicopathological study of 17 cases of ocular surface xanthogranuloma in dogs

OBJECTIVE

To evaluate the clinical, histopathological, and immunohistochemical features of 17 cases of ocular surface xanthogranuloma (OSX) in dogs.

METHODS

Archived records from the Comparative Ocular Pathology Laboratory of Wisconsin (COPLOW) were searched for cases of canine OSX. Cases were evaluated for lipid-laden macrophages and Touton giant cells. Seventeen cases matching those criteria were identified (1993-2018). Clinical and epidemiological data were collected from the submission forms and additional follow-up survey.

RESULTS

Ocular surface xanthogranuloma in dogs presented as small bland nodules. OSX commonly occurred at the limbus (8/17) or cornea (4/17). Three of 17 affected animals were less than 1-year-old and the average age was 6.9 years (range 0.7-14 years). Fourteen of 17 cases did not report any lipid or metabolic abnormalities. Histologically, lesions were composed mainly of dense sheets of vacuolated lipid-laden macrophages and Touton giant cells with scant additional inflammatory cells and an intact overlying epithelium. No recurrence was noted in cases where complete surgical resection was achieved, and medical treatment either pre or post-resection led to only partial resolution.

CONCLUSIONS

Xanthogranulomas are histiocytic lesions characterized by abundant lipid-laden macrophages. The authors use the term, ocular surface xanthogranuloma, to describe nodules with rigidly defined cellular characteristics. Although these lesions share characteristics with human limbal xanthogranulomas, further investigation is needed to suggest the different subsets that have been reported in the medical literature. Complete surgical excision is the most effective treatment for OSX in dogs, and intralesional triamcinolone and topical steroids can be useful adjunctive therapies to surgery.

Ocular Surface Disease in Birds

Avian ocular disease may be primary or a manifestation of systemic disease. Various infectious and noninfectious diseases have been reported to cause ocular pathology. Thorough physical examination and diagnostic testing are necessary to determine a treatment plan.

Avian Oncology: Diseases, Diagnostics, and Therapeutics

Companion birds are increasingly living longer due to improved husbandry, nutrition, and veterinary care. As a consequence, a growing number of geriatric disease conditions are diagnosed and managed by veterinarians. Awareness of bird owners of diagnostic and treatment options for neoplastic diseases in humans and domestic animals has led to increasing demand to provide advanced diagnostic and treatment modalities for companion birds diagnosed with neoplasia. Treatment remains challenging in many companion birds due to the lack of information regarding prognosis and efficacy of antineoplastic treatments in these species. There is no established standard of care for most tumors in companion birds.

Scleral and corneal xanthomatous inflammation in a gray mouse lemur (Microcebus murinus)

Bilateral multifocal corneal opacity was detected in a 4.5-year-old male captive gray mouse lemur (Microcebus murinus) without other clinical ocular changes. Histopathological examination revealed a severe diffuse granulomatous scleritis and focal keratitis with intralesional cholesterol, consistent with xanthomatous inflammation. This is the first report of xanthomatous inflammation in a gray mouse lemur. This condition may be the result of systemic factors (lipid metabolism disorders) and/or local predisposing factors such as hemorrhage or inflammation. The pathogenesis in this case could not be fully determined. Further studies on lemurs are required for a better understanding of their lipid metabolism, as well as for diagnosing and evaluating the incidence of xanthomatous inflammation in these species.

Subcutaneous xanthomatosis in a great white pelican (Pelecanus onocrotalus)

A great white pelican (Pelecanus onocrotalus) was referred for assessment of a subacute-onset, nonpainful swelling located in the pectoral region. Physical examination revealed a firm, round, well-circumscribed subcutaneous mass approximately 10 cm in diameter. Cytological evaluation of a fine needle aspirate of the mass was consistent with a mesenchymal tumor. The mass was excised, and a diagnosis of xanthomatosis was made based on histopathologic results. Avian xanthomatosis is a nonneoplastic condition of unknown etiology. Possible causes of this condition include trauma, metabolic or nutritional disorders. Similar lesions were not observed in the nine conspecifics that were fed the same diet and housed in the same enclosure. To our knowledge, this is the first report of xanthomatosis in the family Pelecanidae.