How canine distemper causes devastating welfare harm and how vaccination prevents it.
Canine distemper causes some of the most prolonged and severe suffering in veterinary medicine. Animals with neurological distemper experience seizures, muscle tremors, and progressive paralysis over weeks or months, with no effective treatment available. The disease is also ecologically significant — distemper outbreaks have caused mass mortality events in African lions, Baikal seals, and various mustelid populations, creating conservation crises with enormous aggregate welfare impact. The profound effectiveness of vaccination makes distemper entirely preventable in domestic dogs, and high vaccination coverage in dog populations protects wildlife through herd immunity that reduces spillover transmission. Vaccination is simultaneously an individual welfare and wildlife welfare intervention.