Vet Reviewed

By The Farmer's Dog | July 26, 2024

Key takeaways:

  • Distemper is highly contagious, and often fatal, killing 50% of adult dogs who are infected. Puppies are even more vulnerable.
  • The best way to protect your dog is by vaccinating them. The distemper vaccine is about 99% effective, and vets consider it a “core” vaccine.
  • Puppies who are too young to be fully vaccinated against distemper (usually those four months or younger) should be kept away from unknown dogs who could infect them.
  • Distemper can spread through breathing and coughing, or through contact with contaminated objects like food and water bowls.
  • If your dog shows any signs of distemper, call your veterinarian right away.

Distemper is a dangerous, highly contagious viral illness that can infect dogs and other animals. While distemper is often fatal, and causes permanent damage in many survivors, you can prevent it by keeping your dog up to date on their vaccinations and being cautious when they’re too young to be fully vaccinated. Read on for details about the disease, how to prevent it, and what to do if you suspect your dog is suffering from it.

How can dogs catch distemper?

Dogs can catch distemper from other dogs and other infected animals. This can happen when they’re near a sick animal who coughs or breathes out germs, or from an object—like a food or water bowl—that the sick animal has been in contact with. If a mother dog is infected with distemper, puppies can contract the disease in utero through her placenta.

What are the signs of distemper?

Dogs who are sick with distemper can show signs including:

  • Coughing
  • Fever
  • Eye or nose discharge
  • Lethargy
  • Vomiting
  • Diarrhea
  • Decreased appetite
  • Trouble breathing

As distemper progresses, dogs may also develop neurological signs like:

  • Walking around in circles
  • Head tilt
  • Lack of coordination
  • Muscle twitches
  • Partial or total paralysis

A dog who shows some of these signs doesn’t necessarily have distemper, but needs to see a veterinarian as soon as possible for diagnosis and treatment. If you notice any of these issues in your dog, call the vet right away.

How do veterinarians diagnose distemper?

First, a veterinarian will ask you some questions about your dog. Then they’ll do a physical examination. They can also perform blood and urine tests to confirm their diagnosis. If your dog has been fully vaccinated against distemper, it’s very unlikely—though not impossible—that they will have the disease. Unvaccinated dogs, however, remain susceptible.

Two puppies smelling a third puppy's head.

What can humans do to protect their dogs from distemper?

The most important and easiest thing you can do to protect your dog from distemper is vaccinate them against the disease, and keep their vaccinations up to date.

Veterinarians consider the distemper vaccine a “core” vaccination, meaning that it’s part of the standard set of shots dogs should receive. The vaccine is nearly 99% effective. Discuss which specific vaccine schedule is right for your dog with your vet.

Once your dog is fully vaccinated against distemper, some vets will test to see if their immunity level is still high enough to give them protection; but, due to the cost of such tests, most of them will instead recommend giving boosters on a predetermined schedule (every one to three years). One way or another, the main thing is to make sure your dog remains immune to the virus.

What can humans do to protect puppies from distemper before their series of vaccinations is complete?

Because dogs aren’t fully vaccinated against distemper until their whole series of shots is complete—and the immunity passed along from their mothers wear off before then—puppies under four months old are especially vulnerable to the illness. As such, you should take extra care to protect young puppies from unfamiliar dogs. This definitely means never letting them play or otherwise interact with dogs whose vaccination status you don’t know. Stay away from dog parks, areas where many other dogs walk (like city sidewalks), daycares or boarding facilities. Beyond that, talk to your vet about how to balance training and socialization with an appropriate level of caution.

How do veterinarians treat distemper?

There’s no cure for distemper, so veterinarians give an infected dog supportive care. They’ll try to prevent the dog from becoming dehydrated, treat any diarrhea or vomiting, administer medication for secondary infections, and generally try to keep them as healthy and comfortable as possible until they’ve recovered.

Around half of adult dogs who contract distemper die, and the numbers are worse for puppies. Many of those who survive suffer permanent damage to their nervous system. But prompt attention from a vet can improve a dog’s chance of a better outcome.

Can humans or house cats catch distemper from dogs?

No. While distemper is highly contagious among dogs, and can be carried by many other animals—including raccoons, skunks, and foxes—humans and house cats cannot catch the virus. (Big cats, like lions and tigers, can—but you shouldn’t be keeping those as pets). House cats can catch a disease sometimes called feline distemper, but that’s caused by a different virus.

What’s the bottom line?

Distemper is very dangerous, and often fatal—but you can prevent it by keeping your dog vaccinated and protecting them from exposure until they’re up to date on their shots. As always, for any specific questions about your own dog’s health, reach out to their veterinarian.