Mammary gland tumors in three male dogs

Mammary gland tumors are very rare in male dogs. In this study, four mammary gland tumors from 3 male dogs (2 intact, 1 neutered) were collected from local animal hospitals. The dogs included two purebred Shih Tzu (1 intact, 1 neutered) and one intact purebred Cocker Spaniel. The mean age of dogs with mammary gland tumors was 9 years (5-12 years). Two dogs had a solitary mass, whereas one dog had two mammary masses. Of the four tumor masses, three were observed in the fourth or fifth mammary glands, and one was observed in the third mammary gland. According to histopathologic examinations, all four mammary masses from three dogs were benign tumors including two benign mixed tumors in one case and two complex adenomas. There were no history of obesity, testicular tumors, diabetes, and sex hormonal therapy in any male dogs with mammary tumors. Surgical excision was the only reported treatment for these tumors. No recurrence or metastasis was recorded up to 25 months after surgery.