Priapism secondary to penile metastasis in a dog.

A 4-year-old, male Newfoundland cross was presented for lethargy, anorexia, and dysuria. The main clinical finding was an enlarged and painful prostate gland. While the dog was hospitalized, priapism developed. Following euthanasia, microscopic examination revealed that a carcinoma involving both bladder and prostate gland had widely metastasized to the penile vasculature.