Cancer is the leading cause of death in dogs over ten years, and assessing and maintaining quality of life during treatment or palliative care is a critical veterinary and owner responsibility.
Canine cancer presents profound welfare challenges throughout the disease trajectory. Diagnosis, treatment, and end-of-life decisions all require careful welfare assessment. Many dogs tolerate cancer treatment well and maintain good quality of life for extended periods. Others decline rapidly or experience treatment-related side effects that compromise welfare. The key ethical obligation is honest, ongoing quality of life assessment — neither under-treating pain to avoid perceived side effects, nor over-treating to extend life at the cost of suffering. Communication between veterinarians and owners about realistic expectations, pain management options, and quality of life indicators empowers better decisions. Timely euthanasia when quality of life cannot be maintained is an act of welfare, not defeat.