Carboplatin chemotherapy in a cat with a recurrent anal sac apocrine gland adenocarcinoma.

An 8-year-old, castrated male, domestic shorthaired cat was presented for evaluation of a perianal mass. The mass was incompletely excised, and histological assessment resulted in a diagnosis of anal sac adenocarcinoma. The cat had a partial response to carboplatin therapy but a short overall duration of response. Necropsy confirmed the original diagnosis as well as metastasis to the regional lymph nodes and lungs.