Canine distemper is a highly contagious, often fatal viral disease affecting dogs and wildlife, causing multi-system illness and long-term neurological damage in survivors - yet entirely preventable through vaccination.
Distemper causes progressive, multi-system suffering over weeks to months. The initial respiratory phase causes breathing difficulty, fever, and extreme weakness. As the virus spreads to the nervous system, seizures, muscle twitching, and progressive paralysis develop. The neurological phase is particularly distressing - dogs with chorea (repetitive involuntary muscle twitching) experience this relentless involuntary movement continuously. Many dogs die during the neurological phase; those that survive often have permanent neurological deficits including seizure disorders and movement abnormalities. The prolonged nature of severe distemper - weeks of escalating suffering - makes it one of the most welfare-significant preventable diseases in companion and wild animal populations.