Pharmacological Treatment of Perianal Gland Tumors in Male Dogs.

The presence of androgen (AR) and estrogen (ER) receptors has been demonstrated both in normal perianal (hepatoid) glands and in perianal tumors. The aim of this study was to demonstrate the relationship between the expression of AR and ER in perianal gland tumors and the effectiveness of antihormonal treatment. The study was performed on 41 male dogs with neoplastic lesions of the anal region. Histopathological evaluation of the lesions revealed 24 adenomas, 12 epitheliomas, and five carcinomas. Treatment was administered orally with tamoxifen at a dose of 1 mg/kg BW and cyproterone acetate at a dose of 5 mg/kg. Tumor diameters were measured regularly with calipers and recorded in millimeters starting with the measurement before treatment, and then after 1, 2, 3, 6, 12, 18, and 24 months of therapy. The results show that hepatoid adenomas that are characterized by high expression of AR and ER receptors respond positively to antihormonal therapy, resulting in complete tumor regression. For locally malignant hepatoid epitheliomas and carcinomas with low expression of AR and ER receptors, antihormonal therapy makes it possible to reduce the size of the tumor, but does not make it possible to cure it completely.