Cancer is the leading cause of death in adult companion animals and advances in veterinary oncology raise welfare questions about treatment intensity.
Companion animal cancer care requires difficult welfare-quality of life judgments that owners and veterinarians must navigate together. Unlike human medicine where patient autonomy guides treatment decisions, veterinary oncology requires proxy decision-making about an animal who cannot express preferences about treatment burdens. The ethical framework must center animal quality of life throughout treatment, recognizing that aggressive curative treatment that creates significant suffering may be less welfare-positive than palliative care focused on comfort and remaining quality time.