Mast cell tumors are the most common malignant skin tumor in dogs, causing local and potentially systemic effects, with welfare outcomes depending on grade and treatment approach.
Mast cell tumors cause both local and systemic welfare impacts. Locally, they cause skin changes including redness, swelling, and ulceration. Mast cell degranulation - spontaneous or triggered by handling - releases histamine causing local wheals, gastrointestinal symptoms, and rarely anaphylaxis. High-grade MCT that metastasize to lymph nodes and organs cause systemic illness. Surgical removal of low-grade MCT is often curative and provides immediate relief. The welfare challenge of MCT is appropriate staging to determine actual risk - preventing both unnecessary aggressive treatment of benign-behaving tumors and inadequate treatment of high-grade disease.