Mast cell tumours are one of the most common skin cancers in dogs, with prognosis highly variable depending on grade, and management requiring a combination of surgery, chemotherapy and palliative care.
Mast cell tumours cause welfare harm through tumour degranulation - releasing histamine and other mediators that cause systemic symptoms including vomiting, diarrhoea and gastric ulcers. Higher-grade tumours cause significant pain and systemic illness. Treatment decisions must balance the welfare benefit of treatment against treatment-associated welfare costs. Quality of life assessment guides these decisions throughout the treatment course.