I.What is Parvovirus

Parvovirus is an infection in dogs caused by the canine parvovirus type 2. The virus is shed in the feces of an infected dog and then ingested by another dog. Anything in the environment that comes into contact with infected feces is considered contaminated. This includes grass, dirt, water, bowls, dishes, blankets, hands, etc. Only a microscopic amount of virus is required to produce infection, so it may not always be obvious when something is contaminated.

Once a dog ingests the virus, it begins to replicate in the tonsils and lymph nodes in the neck and then spreads via the blood to other areas of the body. The virus prefers areas where the cells grow and divide rapidly. The locations where this commonly occurs are the bone marrow and the intestinal lining. Infection in the bone marrow leads to decreased production of white blood cells. Infection of the intestinal lining results not only in the primary symptoms of vomiting and diarrhea, but also allows bacteria from the gastrointestinal tract to leak into the blood stream and spread through the body (sepsis).

Dogs that get parvovirus infections will shed virus in their feces for one to two weeks. The virus is hard to kill and may last for five or six months in the environment. The virus is even hard to remove from kennels and other hard surfaces that are routinely disinfected. A 1:30 dilution of bleach will kill the virus on surfaces that can be bleached.

II.What to Watch for at Home – Symptoms

Whether a dog develops severe disease after it is exposed to parvovirus depends on the number of viral particles it is exposed to, its own immune system, and whether or not there are other diseases present (such as intestinal parasites). Some dogs that are exposed to parvovirus will develop few or no symptoms and will not need veterinary care. These dogs still shed virus in their feces and can be an important source of infection for other dogs, which might be more susceptible to infection and develop more severe disease. Symptoms usually occur in young, unvaccinated puppies. They include:

• Severe vomiting, occasionally with blood


• Severe bloody diarrhea


• Lack of appetite


• Lack of energy


• Fever


• Abdominal pain


• Pale gums


• Dehydration

In very young puppies, only a few days old, the virus can infect the heart and cause heart failure and rapid death. This type of disease is less common than what is described above.

III.The Veterinary Visit – Diagnosis of Parvovirus Infection

Parvovirus infection is suspected in any young, unvaccinated puppy that is vomiting or having diarrhea. The diagnosis is usually confirmed with a fecal test that detects the presence of the virus. A fecal flotation should also be done to check for the presence of intestinal parasites. In many cases, blood work is also necessary. This may show a low white blood cell count, a low red blood cell count (anemia), low blood glucose, low blood protein, or low blood potassium. The blood work results will help guide the veterinarian when he or she is designing a treatment program.

IV.Treatment

Early, aggressive treatment is necessary to save the lives of severely affected puppies. Treatment consists of:

• Placement of an IV catheter


• High volumes of fluid given through the IV catheter. These fluids help correct dehydration and prevent dehydration from ongoing vomiting and diarrhea.


• Antibiotics given through the IV. These antibiotics do not treat the parvovirus infection but help to prevent secondary bacterial infections that might be caused by the spread of bacteria from the intestinal tract to other areas in the body.


• Potassium and glucose added to the IV fluids. These help to treat and prevent low glucose and low potassium, which may cause weakness and depression.


• Dogs that have a very low red blood cell count or a very low protein may need blood or plasma transfusions.


• Medications given through the IV to help control nausea and vomiting.


• Treatment of any intestinal parasites that may have been diagnosed.


• Food is withheld until vomiting is under control. Once vomiting has decreased and the dog seems interested, small amounts of bland food can be offered.

During treatment, an affected dog is hospitalized and must be isolated from other dogs. This prevents the spread of the virus to other susceptible dogs. Many dogs recover in five to seven days with aggressive care. Some dogs may take longer to recover. Treatment can be very expensive and is not always successful. Some dogs will die despite aggressive treatment.

V.Prevention

Parvovirus is preventable. The cornerstone of prevention is vaccination. Vaccination should begin at six weeks of age and continue every month until a puppy is between four and five months old. Vaccination, however, does not completely protect a puppy from disease. For this reason, it is important to be careful about where you take your puppy and what other dogs that it has contact with. Some good guidelines include:

• Do not take your puppy to parks, dog parks, and pet stores where sick dogs or dogs with an unknown vaccination status might have been


• Enroll only in puppy classes or other training classes that require proof of vaccination and do not allow unknown or sick puppies to participate


• Do not allow your puppy contact with unknown or sick dogs.

The video below emphasizes the importance of preventing parvovirus infection.

The information in this article is not intended to diagnose or treat your pet and is not a substitute for appropriate diagnosis and treatment by your veterinarian.