Metastatic simple tubular mammary carcinoma in an ocelot (Leopardus pardalis)

ABSTRACT: Mammary neoplasms are common in domestic felines but are rarely reported in wild felids. On the other hand, understanding the diseases that affect these animals is crucial, considering the importance of wild felines for the environmental balance. Therefore, we aim to describe a case of mammary neoplasia in an ocelot (Leopardus pardalis). A 12-year-old female ocelot housed in a breeding facility located in the state of Paraíba, Brazil, presented anorexia and dehydration for 48 hours, followed by death. The necropsy revealed a firm mass in the abdominal region and a single irregular, ulcerated mass between the caudal abdominal and inguinal mammary glands. All lesions were located on the right side. The masses were multilobulated, irregular, soft, and white on sectioning, with friable and dark (necrotic) areas. Histopathological examination revealed multiple multilobulated, partially encapsulated, non-delimited masses without free borders, composed of ducts, sometimes forming densely solid areas. Metastases were also observed in the lung and the internal muscle of the pelvic limb in the femoral region. Immunohistochemistry (IHC) was performed using anti-cytokeratin and anti-vimentin antibodies. IHC revealed cytokeratin positivity in the mammary gland. Vimentin was negative in the neoplastic cells and positive in the adjacent connective tissue. Thus, histopathological examination led to what seems to be the first diagnosis of metastatic simple tubular mammary carcinoma in an ocelot.