Multiple joint metastasis of a transitional cell carcinoma in a dog.

An 8-year-old castrated male hound mix was referred to the Purdue University Veterinary Teaching Hospital for severe lameness, pollakiuria, and dyschezia. On presentation, the dog was nonweight bearing on the right rear limb and the right carpus was diffusely swollen. Synovial fluid analysis from the right carpus revealed a population of epithelial cells displaying marked anisocytosis, anisokaryosis, multinucleation, and prominent, variably sized nucleoli.