Epidemiology of canine mammary gland tumours in Espírito Santo, Brazil

ABSTRACT

Background: Mammary tumours represent about 50 to 70% of all neoplasms in female dogs and their occurrence is directlyrelated to the reproductive status and patient´s age. The purpose of this research was to apply the Brazilian consensus ondiagnosis, prognosis and treatment of canine mammary tumours and to define the regional epidemiological aspects ofcanine mammary gland tumours in Vitoria metropolitan region (ES, Brazil) between 2012 and 2016 and to correlate themacroscopic characteristics such as lesion size and location of the neoplasm with histopathological diagnosis, tumoursgrade and lymph node metastasis.Materials, Methods & Results: Data were collected from the archives of the Laboratory of Animal Pathology of UVV andmedical records of patients attended at the Veterinary Hospital Prof. Ricardo Alexandre Hippler in 5 years (2012 to 2016). Theanimals were separated into groups by age to facilitate classification in the group with the highest occurrence of neoplasms. Theevaluation of the macroscopic characteristics was performed through the histopathological record described in the pathologylaboratory, for each patient, at the time of the initial evaluation. After descriptive analysis, data was correlated using Spearmanntest, and frequency dispersion was evaluated using chi-square test, both in the software Graph Pad Prism v. 6.01. This studyincluded 255 bitches and diagnosis of 486 lesions, once 48.6% of the dogs had more than one lesion, classified according tothe Brazilian Consensus for Canine Mammary Tumours and graded according to Elston and Ellis system. 86.8% of lesionswere consistent with actual mammary neoplasms, of which 67% were malignant and 20% were benign. Non-neoplastic lesionscorresponded to 7.2% of cases and 5.8% were extra-mammary neoplasms, with an increased incidence of lipomas (39.3%) andmast cell tumours (32.1%). Cross-breed dogs represented 26.7% of cases. Poodles (25.5%), Pinschers (9.8%) and Dachshund(4.7%)...(AU)