Canine Distemper

What is distemper?

Distemper is a highly contagious viral disease of domestic dogs, related to the human measles virus. It attacks several body systems in sequence — typically respiratory first, then digestive, and in many cases the nervous system. Some other species, including ferrets, skunks, and raccoons, are also affected and can carry the virus.

How is the disease spread?

The virus spreads primarily by direct contact between a susceptible dog and an infected one. Coughing and sneezing can spread it over short distances, and discharge from the nose is heavily laden with virus. Puppies and unvaccinated dogs are by far the most vulnerable; infected dogs can shed virus for weeks, even while appearing to recover.

What are the clinical signs?

Signs vary from dog to dog and tend to progress through stages:

• Early: fever, loss of appetite, lethargy, and thick yellow discharge from the eyes and nose
• Progressing: coughing, vomiting, and diarrhea
• Advanced: muscle twitching, "chewing-gum" jaw movements, seizures, and hardened footpads

Many diseases cause coughing, fever, diarrhea, or seizures individually — but this combination is unique to canine distemper. When the diagnosis is in doubt, laboratory testing can confirm it.

What is the treatment?

As with most viral infections, no drug kills the virus itself. Treatment is aggressive supportive care while the dog's immune system fights: antibiotics for the secondary bacterial infections that commonly develop, intravenous fluids for dehydration, cough suppressants, and medication to control seizures. Intensive nursing care is essential and is best accomplished in the hospital.

Do dogs completely recover?

Usually, but not always — and recovery depends heavily on how far the disease progresses. Dogs whose nervous system becomes involved have the most guarded outlook, and some survivors are left with permanent reminders: persistent muscle twitches (myoclonus), recurrent seizures, or damaged tooth enamel in dogs infected as puppies.

How can I prevent my dog from becoming infected?

A very effective vaccine is available, and it is considered a core vaccine for every dog. Puppies receive it in a series of injections starting as early as six weeks of age; the series matters because maternal antibodies can block early doses. Regular boosters maintain protection through adulthood.

Until a puppy has finished the full vaccine series, treat them as unprotected — hold off on dog parks and contact with unfamiliar dogs, and stick to low-traffic areas for socialization.

How common is distemper?

Distemper occurs worldwide. Vaccines have made it rare among healthy, well-cared-for dogs, but the virus persists in stray dog populations and wildlife such as raccoons and skunks — which means an unvaccinated dog is never truly out of reach of exposure.