Canine mammary tumors are the most frequently diagnosed neoplasms in female dogs, typically appearing between 9 and 11 years of age. They may arise as single or multiple nodules, with the posterior mammary glands more commonly affected. Approximately half of all mammary tumors in dogs are malignant, reflecting the significant clinical challenge posed by this disease.
One of the defining characteristics of canine mammary neoplasms is their extensive heterogeneity. Tumors vary widely in their histopathological features, biological behavior, and clinical outcomes. This variability complicates both diagnosis and treatment planning, making individualized assessment essential for managing affected dogs.
Hormones and growth factors play a central role in the development and progression of these tumors. While the influence of reproductive hormones—particularly estrogen and progesterone—has long been recognized, ongoing research is working to clarify the mechanisms by which hormonal signaling shapes tumor initiation, growth, and metastatic potential. Understanding these pathways may help refine prognostic assessments and guide therapy.
Prognosis depends on multiple parameters, including tumor size, metastasis, histological type, degree of malignancy, and the presence of hormone receptors. Early detection and surgical removal remain the cornerstone of treatment, especially for localized disease. Advances in therapeutic strategies—ranging from refined surgical approaches to targeted therapies and adjunctive treatments—are expanding the tools available to veterinary clinicians.
The review emphasizes the importance of integrating pathology, hormonal influences, and individualized risk factors into clinical decision-making. As new therapeutic options continue to emerge, a more nuanced understanding of tumor biology is likely to improve outcomes for female dogs diagnosed with mammary cancer.
Source: Benavente, M. A., Bianchi, C., & Aba, M. (2016). Canine mammary tumors: risk factors, prognosis and treatments.
