Mast cell tumors are the most common skin tumor in dogs and require accurate grading and appropriate treatment decisions to optimize welfare outcomes.
The welfare management of mast cell tumors should be guided by tumor grade, which determines both prognosis and the appropriate intensity of treatment. Over-treating low-grade tumors with aggressive chemotherapy imposes welfare costs without proportionate benefit. Under-treating high-grade tumors allows a highly aggressive malignancy to progress when effective treatment exists. The welfare calculus requires honest histopathological assessment and a frank conversation about what treatment aims to achieve — cure, prolonged remission, or palliative control — and the welfare costs of each pathway.