Cancer pain is widespread in dogs with malignant disease and requires proactive multimodal management to maintain quality of life throughout treatment and into palliative and end-of-life care.
Cancer pain management is a fundamental welfare obligation for dogs with malignant disease. Inadequately managed cancer pain causes persistent suffering that reduces activity, social engagement, sleep quality, and appetite — impairments across every domain of quality of life. The welfare priority is proactive pain management from diagnosis rather than reactive treatment when pain becomes obvious; dogs mask pain effectively, and waiting for obvious signs of distress means pain has been present and undertreated for some time. Bone tumours such as osteosarcoma cause particularly severe pain — the bone destruction and periosteal involvement cause continuous intense pain that requires aggressive multimodal analgesia including NSAIDs, opioids, and gabapentinoids to control adequately. Palliative radiation therapy can substantially reduce osteosarcoma-associated pain for months in some dogs, extending high-quality life beyond what analgesia alone achieves. The relationship between treating the cancer and treating its pain requires honest veterinary-owner communication about the goals of treatment — whether curative, life-extending, or purely palliative — to ensure the chosen approach prioritises the dog's welfare throughout.