Chronic pain in dogs is vastly underdiagnosed because dogs mask pain through evolutionary instinct, and owners and even veterinarians often miss the subtle behavioural changes that indicate ongoing suffering.
The detection of chronic pain in dogs is one of the most important welfare skills for both owners and veterinary professionals, and one of the most poorly executed in practice. The evolutionary logic of pain masking — concealing vulnerability from predators and competitors — creates a systematic welfare blind spot: dogs in significant chronic pain may appear normal to casual observation, engaging in food-motivated activities and maintaining baseline social functioning while experiencing ongoing discomfort. The welfare implications are profound: millions of dogs living with arthritis, dental disease, spinal cord compression, and other painful conditions are not receiving treatment because their pain is not recognised. Structured pain assessment using validated tools — applied regularly, not just during veterinary visits — provides a systematic framework for detection. The most reliable confirmation of prior chronic pain is often post-treatment: dogs that become more playful, more mobile, and more affectionate after analgesic initiation reveal retrospectively the extent of their pre-treatment suffering.