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Frequently Asked Questions About Canine Distemper

September 13, 2016

A Special Statement from The College of Veterinary Medicine

Canine Distemper is a serious contagious infectious disease with no known cure. It is caused by a virus that affects dogs and ferrets as well as some wildlife including raccoons, wolves, foxes, and skunks. Infections are maintained at low levels in stray dog and wildlife populations with occasional outbreaks when conditions support an increase in transmission. Our Frequently Asked Questions provides detailed information about the virus, symptoms and prevention. Because Distemper is a serious virus please contact your local veterinarian immediately if you suspect your dog has been infected.

Frequently Asked Questions

What are the signs of distemper? A significant percentage of dogs have no or very mild clinical signs that are not detected though they do shed the virus and develop immunity. Following a fever which may go unrecognized, the majority of dogs develop upper respiratory signs and some of these progress to severe and sometimes fatal pneumonia. Vomiting and diarrhea may also be present. Respiratory signs in some dogs appear to respond to treatment and resolve as would be expected for other causes of respiratory disease while other dogs experience prolonged illness despite treatment. Severe and often fatal neurologic signs, including seizures can develop around one month after the respiratory infection; this can also occur between one and three months after infection in those that did not show clinical signs.

What is the incubation period between exposure and clinical signs? One to six weeks for the majority of cases with most showing signs within one to four weeks.

When do dogs infected with distemper become contagious? Up to five days prior to the onset of clinical signs. This is complicated though by the number of cases that are shedding without recognizable signs of illness.

How long do infected dogs remain contagious? Up to four months post recovery.

What materials are contagious? Virus is shed in greatest numbers in respiratory secretions such as ocular (eye) and nasal discharge as well as droplets spread by coughing. However, all excretions including vomit, feces, and urine can contain the virus.

How is the virus spread? Direct or close contact between dogs is the most common way it is transmitted. Droplets can travel up to four feet from a sneeze or a cough. Aerosols created while coughing or during cleaning become airborne and can travel many feet. The virus can also travel on objects that it contacts including the people.

How long does the virus survive outside of the dog? The distemper virus is not very durable in the environment surviving only a few hours at room temperature. Sunlight, desiccation (drying out), and common disinfectants are effective at neutralizing it.

What is the best way to protect my dog from distemper? Vaccines are very effective. Most dogs will respond to the vaccine producing protective immunity that will last at least three years, regardless of exposure. For puppies and dogs that cannot be vaccinated additional precautions should be taken to avoid exposure to the virus.

How long does the vaccine take to stimulate immunity? In most dogs over five months of age it will take three to five days. If the dog is exposed during that time it may still develop distemper; often they are milder cases. There are always a small number of dogs who will not respond to the vaccine for a variety of reasons. In dogs under five months, antibodies passed to the puppy through the placenta and during the first day of nursing may prevent the vaccine from working. The time frame that these antibodies become inactivated varies from puppy to puppy and is the reason we give a series of vaccines. Puppies may develop antibodies earlier but should not be considered protected until they complete their vaccination series.

What should I do if I suspect my dog has distemper? If you suspect your dog has distemper, please contact your local veterinarian immediately.

Last updated: 

Tuesday, January 31, 2023 - 12:41pm