Canine mammary gland tumors: risk factors and their epidemiological influence in Manizales-Colombia

Objective. To describe the prevalence of canine mammary gland tumors (CMT) in females in the municipality of Manizales-Colombia from 2014-2017. Materials and methods. A database of 15961 patients was consolidated. The variables analyzed were, breed, age, reproductive history, weight, diet type and clinical characterization of the tumor with the TNM (tumor-node-metastases) staging system. The statistical analysis include Pearson's chi-squared test with Yates correction for continuity and Fisher's exact test (p<0.05), relative risk and odds ratio (CI95%) and Kaplan-Meier estimator for survival analysis. Results. The incidence in purebred dogs was 79.14%, with a peak at the average age of 9.3 years old. Pearson's chi-squared test and the relative risk and odds ratios indicated a high risk for purebreds (p=0.019, 3.96/100, 1.64, respectively). Females of ages between 9 and 12 years old showed a 74% likelihood of developing a mammary tumor. No found significant relation to weight or reproductive stage but indeed a high association with homemade diet (p<0.001). The inguinal mammary pairs were the most affected (6.9%). The Kaplan-Meier estimate showed a higher survival of surgically-intervened patients, with 2013 days of survival after diagnosis with surgery compared to 1484 days without surgery. Conclusions. The study confirmed the relevance of risk factors, breed type, age, body condition and diet type in the mammary tumor presentation. Furthermore, it highlights the need for improving and integrating the veterinary diagnostic information systems, considering their importance in public health.