Mast cell tumors are the most common skin tumors in dogs and range from benign to highly aggressive, requiring prompt diagnosis and care.
Mast cell tumor welfare impacts span from the local welfare effects of tumor presence to the systemic consequences of mast cell degranulation and the welfare burden of treatment. Locally, MCTs cause pruritus (itching), inflammation, and ulceration that are painful and distressing. Manipulating mast cell tumors causes degranulation releasing histamine that causes immediate local swelling and occasionally systemic anaphylactoid reactions, making these tumors particularly important to handle carefully. The surgical welfare impact of achieving adequate margins is significant since extensive tissue removal causes post-operative pain requiring effective analgesia. Targeted therapy with toceranib provides effective systemic treatment for metastatic disease but carries side effects including gastrointestinal upset, anorexia, and fatigue. Prognosis information allows owners to make welfare-aligned treatment decisions balancing treatment burden against expected outcome.