Canine Distemper Virus

What is canine distemper virus?

• Canine distemper virus (CDV) is a paramyxovirus, similar to the virus that causes measles in humans.
• Many wildlife species such as raccoon, coyotes, and skunks can become infected, as well as domestic ferrets, however cats and humans do not get CDV.
• Up to 75% of infected individuals die from CDV. Those that survive often have permanent neurological signs.
• Vaccination for CDV is part of the core vaccine series given to all dogs.

What is the treatment?

Distemper is part of the core vaccine series recommended for all dogs. Vaccination series for puppies involves:

• Three booster vaccines: one at 8, 12, and 16 weeks of age.
• A booster one year following the puppy series.
• Re-vaccination is required at least every 3 years to maintain protective immunity.
• A yearly vaccination protocol may be required depending on individual dog’s risk factors.

Please speak to your veterinarian to establish a vaccine protocol that is best for your dog!

How is distemper transmitted?

• Distemper is spread through aerosol by coughing or sneezing.
• Infected animals can shed the virus for months after signs of disease have passed.
• Wildlife such as Canids (coyotes, wolves, foxes) and Mustelidae (ferret, mink, fisher), and others such as raccoons can be reservoirs which spread the virus to unvaccinated domestic dogs.
• Young puppies under 4 months of age are most at risk. It is recommended puppies have limited contact with wildlife and other dogs of unknown vaccine status until they are fully vaccinated.

What are the signs?

• Initial signs of CDV include fever, eye and nasal discharge, vomiting, and diarrhea.
• Canine distemper has some signs in common with rabies but, unlike rabies, it is not transmissible to humans.

Long-term Signs

If the host is unable to mount an effective immune response, the virus will spread to nervous tissue and cause nervous signs including:

• Seizures
• Twitching
• Partial or complete paralysis
• Lack of co-ordination, compulsive movements
• Long term CDV may also be characterized by overgrowth of the skin on the foot pads and nose (‘hardpad’ disease).

How is it diagnosed?

• Immunofluorescent assay (IFA) or polymerase chain reaction (PCR) can be performed on urine, cerebrospinal fluid, or blood.
• Skin biopsy of foot pad or haired skin can be taken to look for presence of the virus.

What is the treatment?

There is no anti-viral treatment for CDV. Once infected, therapy is based on supportive care:

• Providing fluid support if animal has vomiting or diarrhea.
• Reduce chance of acquiring secondary bacterial infections; do not feed raw diet, clean and disinfect dishes and toys regularly.
• Keep dog isolated to prevent spread of infection.

Written by Dr. Connie Tuck, DVM