Canine Parvovirus

by Lorie Huston, DVM

Canine parvovirus is a severe, potentially fatal gastrointestinal disease that infects dogs. 

Puppies and young dogs are most susceptible and tend to have the most severe infections, but dogs of any age that are unprotected against parvovirus can get the disease.

Symptoms of Parvovirus in Dogs

Parvovirus attacks the intestinal tract, essentially destroying the inner lining of the intestines. Symptoms most commonly seen with parvovirus include:
  • vomiting
  • diarrhea, often bloody diarrhea
  • lack of appetite
  • depression, usually severe depression
  • fever
  • subnormal temperature  (especially in the later stages of the disease)
  • dehydration

The dehydration seen with canine parvovirus is profound and life-threatening. Death from parvovirus occurs in part as a result of the dehydration.

Another less commonly seen form of parvovirus affects the heart muscle. This form of parvovirus causes the cells in the heart muscle to become inflamed and die. The cardiac form of parvovirus affects young puppies most commonly and is frequently fatal.

Parvovirus is caused by a virus that is passed from one dog to another through fecal-oral contact. 

This means that your dog can become infected with parvovirus by being exposed to a fecal sample from a dog that is carrying the virus.

Treatment of Canine Parvovirus

There is no specific cure for canine parvovirus. The goal of treatment is to support the infected dog in the hope that the dog’s immune system will eventually be able to defeat the infection. As a result, treatment of parvovirus is basically supportive care, through intensive care is usually necessary in order for the dog to survive.

The most important part of treatment for parvovirus is fluid administration. 

Fluids are given intravenously to replace the fluid loss caused by the vomiting and diarrhea in an attempt to keep the dog hydrated.

In some cases, blood or plasma transfusions may be necessary in addition to fluid therapy.

Antibiotics are often administered in treating parvovirus to help prevent secondary bacterial infections. Secondary bacterial infections are a threat because the parvovirus causes suppression of the bone marrow and a weakened immune system.

Anti-emetic medications are frequently a part of the treatment for parvovirus as well. Anti-emetic medications help prevent vomiting and can be helpful in controlling nausea as well.

Prevention of Parvovirus in Dogs and Puppies

Vaccination against canine parvovirus is available and is considered to be a core vaccine (a vaccine that is recommended for all dogs).

Puppies can be vaccinated against parvovirus as early as 6-8 weeks of age. The vaccine should be repeated at 3-4 week intervals until the puppy is between 14-16 weeks of age. Some veterinarians believe that it is safest to administer the last vaccine in the series at 16 weeks of age or older.

The canine parvovirus vaccine should be repeated in one year. After that, the vaccine should be re-administered at least every three years, although some veterinarians administer the vaccine on a yearly basis.

Alternatively, titers can be measured in place of routine vaccination. 

The titer may indicate that dog is well-protected against parvovirus and does not need to be re-vaccinated. It may also be within a questionable range, in which case the vaccine should be administered.

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