Identifying the Risk Factors for Malignant Mammary Tumors in Dogs: A Retrospective Study.

Mammary cancer is one of the main causes of death in female dogs worldwide, considering that many risk factors are involved in its development. This study aimed to elucidate the relationship between epidemiological and clinical risk factors with the histopathological diagnosis of malignant mammary tumors in dogs treated at the Veterinary Hospital of the Federal University of Uberlândia, which has one of the first veterinary oncology services in Brazil. A retrospective matched case-control study was conducted to identify risk factors for the development of malignant mammary tumors in dogs. The variables analyzed were size dog, breed, housing, type of diet, and body score. Potential risk factors were selected by univariate analysis (p < 0.25) before multivariate forward binary logistic regression. The most frequent benign tumor was the benign mixed tumor (35.2%), and the most frequent malignant tumor was the mixed carcinoma (27.4%). Size dog, breed, housing, and overweight are predictors of malignant mammary tumors in dogs. The highest risk of developing malignant mammary tumors is associated with large female dogs, Yorkshire or Poodle breeds, living outside the home, or being overweight.

Tyrosine kinase inhibitors as an alternative treatment in canine mast cell tumor.

The current gold standard treatment for canine mast cell tumors (MCT) uses vinblastine sulfate (VBL) as chemotherapy, although tyrosine kinase inhibitors (TKI) have recently been shown to be worthy candidates for treatment. This systematic review aimed to analyze the overall survival (OS), progression-free survival (PFS), overall response rate (ORR), and complete (CR) or partial response (PR) in dogs with MCT treated with TKI compared to standard VBL treatment. The systematic review was registered in the Open Science Framework (OSF) database under the identifier 10.17605/OSF.IO/WYPN4 (https://osf.io/). An electronic search was performed in nine databases. References from eligible studies were also selected to find more registers. A total of 28 studies met the eligibility criteria, and one more was recovered from the references of eligible studies, totaling 29 selected studies. The overall response rate, complete response, and partial response were higher in dogs treated with tyrosine kinase inhibitors than in dogs treated with vinblastine. The overall survival and progression-free survival of vinblastine-treated dogs were higher compared to tyrosine kinase inhibitors-treated dogs. Dogs with mutated KIT treated with tyrosine kinase inhibitors have longer overall survival and progression-free survival compared to those treated with vinblastine. It is important to consider the limitation of the study which should temper the interpretation of the results, videlicet, the extracted data lacked sample standardization and included variables such as animal characteristics, mutation detection methods, tumor characteristics, and treatment types which may have influenced the outcome of the study. Systematic review registration: https://osf.io/, identifier: 10.17605/OSF.IO/WYPN4.