What is Parvo?

Canine parvovirus (parvo) is a highly contagious viral disease, first appearing in 1978. It attacks the gastrointestinal tract and cardiovascular systems of dogs. The main source of the virus is the feces of infected dogs, which can have a high concentration of viral particles. Susceptible animals become infected by ingesting the virus. The virus attacks rapidly dividing cells in a dog’s body, most severely affecting the intestinal tract. Parvovirus also attacks the white blood cells, and when young animals are infected, the virus can damage the heart muscle and cause lifelong cardiac problems.

Puppies and adolescent dogs who are not vaccinated are most susceptible to the virus. Parvo affects most members of the dog family (wolves, coyotes, foxes, etc.). Breeds at a higher risk are Rottweilers, Doberman Pinschers, Labrador Retrievers, American Staffordshire Terriers and German Shepherds. Parvo may affect dogs of all ages, but is most common in dogs less than one year of age. Young puppies less than five months of age are often the most severely affected and the most difficult to treat.

General symptoms of parvovirus are sudden onset of bloody diarrhea, lethargy, severe vomiting and loss of appetite that can lead to life-threatening dehydration. A puppy with a bloody diarrhea could have a parasite problem, a virus other than parvovirus, a stress colitis, or may have eaten something that disagreed with him or injured and blocked his digestive tract. It’s crucial that you see your vet for an accurate diagnosis.

Parvovirus is highly contagious and resistant to the effects of heat, detergents and alcohol so it can remain in the environment for up to a year after an infected dog has been there. This is why the virus can reoccur especially in unvaccinated dogs or in dogs where vaccinations have lapsed. Due to its stability, the virus is easily transmitted via the hair or feet of infected dogs, contaminated shoes, clothes, and other objects. Highly resistant, the virus can live in the environment for months, and may survive on inanimate objects such as food bowls, shoes, clothes, carpet and floors. This means that even if your dog never goes to the park or mixes with other dogs, it can be exposed to virus in the environment. Dogs that become infected with the virus and show clinical signs will usually become ill within 7-10 days of the initial infection.

Veterinarians diagnose parvovirus on the basis of clinical signs and laboratory testing. The Enzyme Linked ImmunoSorbant Assay (ELISA) test has become a common test for parvovirus. The ELISA test kit is used to detect parvovirus in a dog’s stools, and is performed in the vet’s office in about 15 minutes. Because this test is not 100% sensitive or specific, your veterinarian may recommend additional tests and bloodwork.

The best method of protecting your dog against parvovirus infection is by vaccinating with premium vaccines. Parvovirus should be considered a core vaccine for all puppies and adult dogs. Generally, the first vaccine is given at 6-8 weeks of age and a booster is given at four-week intervals until the puppy is 16-20 weeks of age, and then again at one year of age. A puppy’s vaccination program is not complete before four months of age. Older dogs who have not received full puppy vaccination series may be susceptible to parvovirus and should also receive at least one immunization. Consult with your veterinarian about how often your dog will need to be revaccinated.

Because parvovirus can live in an environment for months, you will want to take extra care if there has been an infected dog in your house or yard. Some things are easier to clean and disinfect than others—and even with excellent cleaning, parvovirus can be difficult to eradicate. Parvo is resistant to many typical disinfectants. A solution of one part bleach to 32 parts water can be used where organic material is not present. The infected dog’s toys, food dish and water bowl should be properly cleaned and then disinfected with this solution for 10 minutes. If not disinfected, these articles should be discarded. You can also use the solution on the soles of your shoes if you think you’ve walked through an infected area. Areas that are harder to clean (grassy areas, carpeting and wood, for example) may need to be sprayed with disinfectant, or even resurfaced.

Although there are no drugs available that can kill the virus yet, treatment is generally straightforward and consists of aggressive supportive care to control the symptoms and boost your dog’s immune system to help him win the battle against this dangerous disease. Dogs infected with parvovirus need intensive treatment in a veterinary hospital, where they receive antibiotics, drugs to control the vomiting, intravenous fluids and other supportive therapies. Should your dog undergo this treatment, be prepared for considerable expense—the average hospital stay is about 5-7 days.

Please note that treatment is not always successful—so it’s especially important to make sure your dog is vaccinated.