Parvoviral Enteritis (Parvo) in Dogs

Parvovirus, also known as Parvoviral Enteritis or “Parvo,” for short, is a virus that can cause severe infection in puppies and dogs. It invades and destroys rapidly growing cells in the intestine, bone marrow and lymphoid tissue resulting in nausea, vomiting, and severe hemorrhagic (bloody) diarrhea. The invasion of the bone marrow cells causes a decrease in the white blood cell count leading to increased susceptibility to bacterial infections and sometimes to a shock-like condition called endotoxemia. The disease can vary from mild to fatal if not properly treated.

Parvovirus is extremely contagious to other dogs. Infection is generally attributed to the ingestion of material contaminated by dog feces and can occur when a dog smells or licks the ground. Direct contact with another dog is not necessary for infection. Parvovirus is shed in the feces of infected dogs for approximately two weeks after initial ingestion and can live in the environment for years. The virus is species-specific and is not contagious to cats or humans.

Dogs at the highest risk for infection are unvaccinated puppies or those who have not yet completed their vaccine series. It is most common in dogs less than 8 months old. Especially susceptible breeds include Doberman pinschers, Rottweilers, German shepherd, Staffordshire terriers, black Labrador retrievers, and dachshunds. Dogs of all ages can be infected, but puppies and younger dogs are most susceptible. Intact male dogs may also be susceptible for unknown reasons.

Unsanitary and/or overcrowded kennels may increase the chance of infection and concurrent infection with parasites, other bacteria or viruses may also increase susceptibility to infection. Parvovirus is nearly 13 times more common in unvaccinated dogs. Proper vaccination of your dog can best prevent the disease.
Parvovirus is an acute and serious disease, not a chronic condition. Virtually all cases need proper diagnosis and hospitalization. If your dog is having active symptoms, it is important to see your veterinarian. Parvovirus can be fatal if not properly treated.

What to Watch For

Clinical signs in dogs generally are seen 3 to 14 days after exposure to the virus. Signs may include:

Diagnosis of Parvoviral Enteritis in Dogs

Diagnosis is usually based on clinical signs. Diagnostic tests are needed to recognize parvovirus and exclude other diseases. Tests may include:

Treatment of Parvoviral Enteritis in Dogs

Your veterinarian will probably recommend hospitalization. Therapy is dependent upon the severity of the clinical symptoms and is aimed at treating the dehydration, controlling vomiting and diarrhea, and preventing secondary infection. If the bacterial infection can be prevented and dehydration treated, clinical signs will usually resolve in 2 to 5 days. Therapy may include:

Home Care

At home, allow your dog to rest and regain his strength. Once vomiting and diarrhea have stopped, encourage water intake. Offer your dog a small amount of water and a bland diet. Your veterinarian may recommend a prescription diet.
It takes a few days for stools to normalize. Nevertheless, it is important that you pick up feces and keep the environment clean. It is likely that the feces will contain the virus and other dogs may contract the disease.
If your dog is not eating or drinking, is continually tired, vomiting and/or still has diarrhea, call your veterinarian.

Preventative Care

Prevention is possible by vaccinating your dog regularly to help prevent infection. (NOTE: Immunity to parvovirus develops after infection, but it is necessary to schedule booster immunizations (“shots”) with your veterinarian to protect from other viruses). It is now recommended that the last vaccine in the puppy series be at approximately 20 weeks. Previously the last vaccine for parvovirus was recommended closer to 16 weeks.
Keep your dog away from the fecal waste of other dogs when walking along neighborhood streets or parks. If your dog leaves his own “deposit” be sure to remove it and dispose of it at home.
You should also minimize contact of unvaccinated puppies with other dogs that may be sick or unvaccinated. This should include avoiding areas where other sick dogs may have been (parvo can live in the environment for 2 years). Your dog is most at risk until fully vaccinated (usually 20 to 24 weeks of age).

In-depth Information on Parvoviral Enteritis in Dogs

Parvovirus can have symptoms similar to many other diseases. These diseases may include:

Veterinary care should include diagnostic tests and subsequent treatment recommendations.

In-depth Information on Diagnosis

Diagnostic tests are needed to recognize parvovirus and exclude other diseases, including:

Additional diagnostic tests may be recommended on an individual dog basis, including:

In-depth Information on Treatment

Treatments for parvovirus may include one or more of the following:

The most successful outpatient treatment established to date includes subcutaneous fluid therapy, antibiotics, drugs to control vomiting, glucose and potassium supplementation as needed, and careful dietary management. This may require daily visits to your veterinarian. They will sometimes create various precautions when treating your dog to minimize the chance of contamination of their hospital. Some dog owners learn to give subcutaneous fluids and injectable medications at home.

The Prognosis for Dogs With Parvovirus

  Following recovery from parvo, allow your dog to rest and regain his strength. Feces should be picked up and kept from other dogs because it most likely contains the virus.
  Parvovirus is extremely resistant to many disinfectants. The recommendation for cleaning areas possibly contaminated with parvovirus includes the use of diluted bleach (diluted to 1 part bleach to 20 parts water) or quaternary ammonium disinfectants (such as Roccal-D, Parvosol, and others). Remove all soiled material first then spray areas well with either of these products and let sit for 10 minutes before rinsing.

If your dog is not eating or drinking, is continually tired, vomiting and/or still has diarrhea, call your veterinarian. It takes a few days for stools to normalize.