Risk Factors Associated with Solid Oral Tumors in Dogs: A Case-Control Study in São Paulo, Brazil

Marcella Collaneri Carrilho¹Katia Pinello²Helena Sofia Salgueiro²Laura Sichero¹Denner Santos Dos Anjos³Guilherme da Silva Rogério¹Andrigo Barboza de Nardi⁴Maria L.Z. Dagli^1*

• ¹University of São Paulo, São Paulo, Brazil
• ²Universidade do Porto Instituto de Ciencias Biomedicas Abel Salazar, Porto, Portugal
• ³Eletro-Onkovet Service,, Franca, Brazil
• ⁴Universidade Estadual Paulista Julio de Mesquita Filho, São Paulo, Brazil

Cancer, a multifactorial disease, remains a leading cause of mortality in dogs and cats, emphasizing the importance of veterinary oncology. Solid oral tumors represent approximately 6% of malignant neoplasms in dogs, with melanoma, squamous cell carcinoma, and fibrosarcoma identified as the most prevalent types. This case–control study examined internal and external factors associated with the development of solid oral tumors in dogs. Owners of 80 dogs diagnosed with solid oral tumors and a control group of 95 healthy dogs completed a structured epidemiological questionnaire. Univariate and multivariate analyses identified significant associations between groups regarding age, weight, reproductive status, specific dietary habits, and environmental exposures, such as barbecue smoke and professional dental cleaning. While these findings suggest potential risk factors, the study's observational design and potential for residual confounding require cautious interpretation. These results warrant further investigation through prospective studies to support evidence-based prevention strategies for oral cancer in dogs.