Parvovirus in Dogs

Parvovirus is a virus that is found in all environments and all seasons (survives in the environment for more than 7 months) that affects dogs. People and cats are not infected by parvovirus (cats are affected by a similar virus known as distemper). Unvaccinated and partially vaccinated puppies (younger than 8 months old) and unvaccinated adult dogs are most susceptible to the devastating parvovirus infections. A puppy may get infected when his/her mouth comes in contact with the virus in feces, contaminated soil, or other materials that are infected with this virus, which commonly happens on a simple walk.

Most common exposure to parvovirus ocacurs in dog parks, grassy reas, and overcrowded housing situations. Once ingested, the incubation period (time between exposure and clinical signs) is 3-14 days. The factors that determine whether a puppy will get sick from their exposure to parvovirus can vary and may include: the amount of exposure to the virus, the number of vaccines, and the overall health at time of exposure (ex. stressed animals and those housed in crowded areas are more likely to become sick after exposure). Once infected, these animal shed (release) a HUGE amount of the virus in their feces, saliva and vomit, which other dogs may get sick from. Dogs that survive this infection can continue to shed (release) the virus for 2-3 weeks. Since the virus is built to be hardy, it is resistant to many household cleaning agents and can be difficult to eradicate (10% bleach is recommended for cleanup). Any dog can get parvovirus but some breeds are highly susceptible including Doberman pinschers, rottweilers, pit bulls, German shepherds and dachshund breeds.

Vaccination is the single most important preventative effort. Puppies should be vaccinated against parvovirus (with DHPP vaccine) starting at 8 weeks of age and should receive the DHPP vaccine every 3-4 weeks until they are 12 weeks of age to be considered vaccinated. Puppies that have not received the full vaccination series should not be allowed to go to dog parks, play on grass, and frequent areas where unvaccinated dogs may be present (including walks in the neighborhood). Puppy classes pose little risk to other participating puppies as long as they have had at least one vaccine, are healthy and are not showing clinical signs of parvovirus infection. Please be sure to check with the facility your puppy may be attending puppy classes at for more information on how they prevent the spread of parvo. If you suspect that your puppy has symptoms consistent with parvovirus or may have been exposed, you should bring him/her into Encina Veterinary Hospital for testing.

Parvovirus destroys the lining of the small intestine and depletes the body of white blood cells that are needed to fight infection. In very young puppies parvovirus can cause permanent damage to the muscles of the heart. The virus acts on the lining of the small intestine and causes it to be sloughed off, which allows blood and liquids to leave the body and bacteria from the gut to enter the body. For this reason the most common symptom of the parvovirus infection is bloody, foul smelling liquid diarrhea. Other clinical signs include lethargy/decreased activity, loss of appetite, and vomiting. Severely ill animals can develop severe dehydration, sepsis, shock and death. If animals are housed together they can develop these symptoms within a couple days of one another. Once symptoms occur these pets should be separated and presented to a veterinarian for diagnostics and treatment.

A quick fecal test can be performed at the veterinary clinic to confirm this infection. Bloodwork is necessary to determine the white blood cell count and overall health status. These test are very important as they help guide the overall treatment plan. Fecal sample may be sent out to the laboratory for analysis as young puppies can be concurrently infected with parasites such as worms and giardia, which should also be treated.

Treatment for parvovirus infection should be performed as soon as diagnosed and in a veterinary hospital such as Encina Veterinary Hospital. Treatment involves intravenous fluids for rehydration, antibiotics, pain medication, anti-emetic, and correction of electrolyte or blood sugar imbalances. While in the hospital, patients will also be monitored for low blood pressure and low and/or high temperatures.
Severely affected animals such as those in shock or septic will require longer and more involved treatments. Puppies and adult dogs that are treated for parvovirus in a veterinary hospital will be placed in an isolation ward as they are contagious to other unvaccinated dogs. Because parvovirus is such an aggressive virus and highly contagious, dogs who are positive for parvo are often isolated from non-infected dogs.

With the appropriate treatment led by a veterinarian, parvo can be beat and your dog can live a healthy life. However, it’s important to know that the response to treatment plays a huge role in the chances a dog has at beating parvo. Without appropriate treatment as soon as clinical signs are noted, the chances of survival decrease. In untreated animals, severe illness most often results in death.

If you feel your dog may have been exposed to the parvovirus and is now positive, please give us a call immediately: (925) 937-5000

Maryam O’Hara DVM