Cancer is the leading cause of death in dogs over 10 years, and treatment decisions require careful consideration of welfare alongside survival benefit.
Cancer treatment decisions for dogs require centering quality of life rather than survival extension as the primary metric. The question is not simply "can we treat this?" but "what is the welfare trajectory with and without treatment?" Aggressive treatment that extends life while causing significant suffering is not welfare-positive if the additional time is poor quality. Palliative care — focused on comfort and enjoyment rather than cure — is a welfare-positive choice for cancers with poor prognosis or when owners cannot pursue aggressive treatment. The welfare obligation is ensuring dogs do not experience unmanaged pain, regardless of which treatment path is chosen.