Canine distemper virus is a virus that can cause many different signs. It may affect the nervous, respiratory, and gastrointestinal systems.
The most commonly infected are the young, unvaccinated puppies. However, any unvaccinated dog has the potential of developing the virus if exposed. Puppies that are kept in stressful housing environments are predisposed to the virus.
CDV is transmitted through bodily secretions and can have wildlife hosts such as coyotes and raccoons. The virus can be shed in these secretions for 10-60 days. The virus is usually transmitted via aerosol exposure (through the air). Once it is inhaled, it replicates in lymphoid tissues. Within two weeks, it penetrates into the central nervous system and other tissues such as lung, intestinal, and skin.
The clinical signs of CDV include nasal and ocular discharge and sneezing, diarrhea, changes on the footpads and nose called hyperkeratosis, and neurologic signs such as seizures, paralysis, vestibular signs, and blindness.
Diagnosis of CDV can be quite difficult. There can be some abnormal signs on retinal exam and lab work may show a low number white blood cells. Tissues may be biopsied and tests can be run on these samples to check for the virus antigen.
Treatment is supportive care. Once dogs start showing neurologic signs, the prognosis is poor. This is why it is so important to vaccinate puppies starting at 6-8 weeks of age every 2-3 weeks until they reach 16 weeks of age. At that point, a booster is needed at one year and then every three years.
Canine distemper virus is almost always a fatal disease that can be easily prevented with vaccination.