INCIDENCE OF MAMMARY NEOPLASMS IN BITCHES AND QUEENS SEEN AT THE VETERINARY HOSPITAL OF THE UNIVERSITY OF SANTA CRUZ DO SUL

Abstract

Mammary tumors are frequent in bitches and cats. This study aimed to evaluate the frequency of canine and feline mammary tumors, their size, histopathological type and the relationship between the occurrence of mammary neoplasms and the fertile status of the animal. The data in this study are from patients treated at the HV-UNISC-RS during the period from December 2020 to August 2021. The tumors of 21 females, 19 bitches and 2 cats were analyzed, with a mean age of around 9 years, ranging from 2 to 13 years. Of these, 90.40% were not neutered. Histopathological analysis of mammary chains resulted in the diagnosis of 49 tumors, of which 48 were diagnosed as neoplastic and 1 presented non-neoplastic alterations. Regarding the biological behavior of neoplasms, 81.25% were malignant and 18.75% benign. The size ranged from 0.7 to 10 centimeters in diameter. In cats, tubular carcinoma was more prevalent (60.00%), with carcinoma in situ (20.00%) and phyllodes tumor (20.00%) also being reported. In bitches, it was carcinoma in mixed tumor (34.88%), followed by tubular carcinoma (18.60%), micropapillary carcinoma (13.95%), malignant adenomyoepithelioma (6.66%), benign adenomyoepithelioma (4.65%), benign mixed tumor and tubular adenoma (4.65%), carcinoma in situ, solid carcinoma, tubulopapillary carcinoma, ductal adenoma and fibroma (2.32%). The incidence of mammary tumor is higher in bitches due to prolonged exposure to estrogen. Most of the females with neoplasms were not neutered or had used exogenous hormones, thus emphasizing the importance of castration of canine and feline females and the contraindication of the use of progestogens.