Tyzzer's disease in a red panda (Ailurus fulgens fulgens).

A debilitated 9-yr-old female red panda (Ailurus fulgens fulgens) with a recent history of corticosteroid administration displayed anorexia, depression, and diarrhea for 2 days. Blood work revealed a moderate nonregenerative anemia, leukocytosis, hypokalemia, hyperbilirubinemia, and mildly elevated alanine aminotransferase and aspartate aminotransferase. Serology was negative for occult heartworm, Toxoplasma gondii, feline leukemia virus, feline infectious peritonitis, feline immunodeficiency virus, and canine distemper virus. Electron microscopy of the feces demonstrated corona-like virus particles. The panda died 3 days after initial presentation. Histologic findings included multifocal, acute, hepatic necrosis and diffuse, necrotizing colitis. Liver and colon lesions contained intracellular, curved, spore-forming, gram-negative, silver-positive rods morphologically consistent with Clostridium piliforme. This panda most likely contracted Tyzzer's disease subsequent to having a compromised immune system after corticosteroid administration and concurrent disease.