Canine distemper virus causes severe multi-system disease with significant welfare impacts in unvaccinated dogs and can threaten wildlife populations when transmitted from domestic dogs.
Distemper causes a prolonged and distressing illness that progresses through respiratory, gastrointestinal and neurological phases. Dogs with advanced distemper experience seizures, progressive neurological dysfunction and physical deterioration over weeks. The neurological damage caused by distemper can cause permanent disability in survivors. The disease is prolonged, often requiring weeks of intensive supportive care with uncertain outcome. The welfare impact on individual dogs is severe, and the disease is almost entirely preventable through vaccination. Spillover to wildlife populations including endangered carnivores represents both a conservation and welfare tragedy that can be reduced through domestic dog vaccination in at-risk areas.