High-grade (Grade III) mast cell tumours in dogs carry a poor prognosis and require aggressive multimodal management, raising complex welfare and quality-of-life decisions for owners and veterinary teams.
High-grade MCT management involves difficult welfare trade-offs — treatment options carry significant side effects (bone marrow suppression, GI toxicity) while the disease itself causes local and systemic welfare impairment. Owners face the genuinely difficult decision between pursuing aggressive treatment with uncertain benefit and predictable side effects, and palliative care that prioritises comfort over survival time. Neither approach is ethically superior to the other — the right choice depends on the individual dog's condition, temperament, and the owner's capacity for intensive nursing care. Quality-of-life assessment at every appointment using validated tools, and honest communication about prognosis and treatment burden, enables informed owner decision-making that centres dog welfare appropriately.