Cancer is one of the leading causes of death in older dogs, and quality of life considerations during diagnosis, treatment, and end-of-life care are central to modern veterinary welfare practice.
Dog cancer welfare requires honest assessment of quality of life throughout the illness trajectory. Treatment decisions should be guided by the dog's experience, not owner reluctance to accept prognosis. Some treatments produce meaningful quality time with acceptable side effects; others impose treatment suffering that exceeds realistic benefit. Pain management in cancer dogs has improved significantly - modern multimodal analgesia can dramatically improve quality of life. Validated quality of life tools including the HHHHHMM scale give owners objective frameworks for decision-making. Euthanasia when quality of life deteriorates below an acceptable threshold is a profound act of welfare that prevents prolonged suffering - a responsibility that dogs cannot exercise for themselves.