Canine Distemper


What is Canine Distemper?

Canine distemper is a very contagious and deadly virus that affects a dog’s respiratory, gastrointestinal and central nervous systems, as well as the conjunctival membranes of the eye. Dogs are not the only animal susceptible to this virus. Ferrets and wildlife such as raccoons, coyotes, wolves, foxes and skunks are at risk as well. Dogs of all ages are susceptible to distemper, but those with suppressed immune systems and dogs that are un-vaccinated or not completely vaccinated are at the highest risk for contracting the virus.  Prognosis for recovery is very guarded for this disease. Those who do recover usually have lasting neurological deficits for the rest of their life.


What are the symptoms of Canine Distemper?

The virus starts by invading the tonsils and lymph nodes, and as it progresses it spreads to the respiratory, urinary, digestive and nervous systems.

Initial symptoms of distemper include:

  • Fever

  • Watery/red eyes

  • Clear discharge from the nose and eyes

  • Vomiting

  • Diarrhea

  • Decreased appetite and anorexia

As the disease advances, symptoms will progress to:

  • Paralysis

  • Off behavior and agression

  • Seizures, tics or tremors

  • Retinal discoloration

  • Hardening of the pads of the feet


How is Canine Distemper diagnosed?

Diagnosing distemper is usually based on the dog’s medical history, vaccination status, clinical signs, physical exam and laboratory testing. A dog with a history of exposure to an infected dog or lack of their own vaccination with the visible signs of illness may be suspected of having distemper.

Blood tests including a complete blood cell count and chemistry screen will provide important information in regards to organ function and overall health. Chest x-rays may also be recommended to check for pneumonia, which can be associated with distemper. For a specific diagnosis of canine distemper a variety of samples can be submitted to the lab for PCR testing to confirm the presence of canine distemper virus. Depending on the clinical signs, the veterinarian will decide what samples are best to submit. They include whole blood, deep pharyngeal and conjunctival swabs, fecal samples or cerebrospinal fluid.

How is Canine Distemper treated and prevented?

Since it is a virus that causes distemper, there is no specific drug that can sure it. Treatment is centered on supportive care. This means that the secondary problems that come up in the course of the infection are addressed individually with the goal of keeping the patient alive long enough for an immune response to generate. Hospitalization, isolation and intensive care is needed to attempt to treat canine distemper.

Treatment will include:

  • IV fluid therapy: to replace the fluid losses from vomiting and diarrhea

  • Antibiotic therapy:  to prevent or treat secondary infections, such as pneumonia

  • Anti-emetics: to control nausea and vomiting

  • Anti-seizure medications: to control any seizures, tics or tremors


Vaccination is available against canine distemper, it is part of the DA2PP core vaccine given to dogs (the “D” in the vaccine name stands for distemper). Canine distemper is preventable with the appropriate vaccination schedule. Vaccination should start in puppies at 8 weeks of age then boostered at 12 weeks. Puppies vaccinated earlier than 8 weeks may need a third booster to make sure proper immunity is obtained. Vaccination is repeated one year later, then changes to a 3-year vaccination schedule.