Retrospective study of mammary lesions in bitches - Uberlândia, MG, Brazil

ABSTRACT

Background: Mammary tumors are a type of neoplasia that are most commonly found in female dogs and are mostly malignant. The aim of this study, performed in the Laboratory of Veterinary Pathology of the Federal University of Uberlândia (LVP-FUU) from 2004 to 2014, was to determine the prevalence of mammary tumors in bitches and to verify the relationship between the epidemiological factors (age and breed) and clinicopathological aspects (ulceration, tumor size, and malignancy) in the occurrence of tumors.Materials, Methods & Results: A retrospective study was carried out using histopathological information retrieved from the LPV-UFU database. We collected the information on age and breed of female dogs, as well as about the location, macroscopic aspects, and histological diagnosis of mammary lesions. Only female dogs were considered for this study; a total of 911 histo-pathological protocols (with only one diagnosis) were analyzed along with 36 protocols that presented more than one diagnosis of mammary tumor. The age of animals ranged from one to 20 years, and the mean age was 9.99 years. The most affected breeds of dogs were Cross breed (39.56% - 288/728) and Poodle (20.19% - 147/728). The inguinal glands were most affected by the malignant tumors (P< 0.05). A prevalence of tumors bigger than 5 cm in diameter (T3) was observed in the elderly animals (P= 0.0154) and in the inguinal mammary glands (P= 0.044). Simple carcinoma was the most frequent histological type.[...]