Mammary gland tumours in male dogs: a hormonal and tumour marker study

Seven male dogs with clinically and histologically confirmed mammary gland tumours were included in this study. All dogs were sexually intact. Median age at diagnosis was 9.4 yrs. Five were purebred and the rest were mongrels. Six dogs had a solitary growth whereas in one animal multiple growths were seen. All tumours were histologically benign. Simple adenomas with mixed acinar and papillary pattern were observed. All tumours were removed surgically. Healing was perfect in all cases without any postoperative complications. No recurrence was recorded up to six months post-surgery. The expression of sex hormones and p53, cox-2 and MMP-7 tumour marker genes was strong in the majority of cases. Although uncommon, mammary tumours do occur in male dogs.