Articles & News
Canine Parvovirus
10/18/2005
What is Canine Parvovirus?
Canine Parvovirus (CPV) infection is a relatively new disease that appeared in 1978. Because of the severity of the disease and its rapid spread through the canine population, CPV has aroused a great deal of public interest. It is a highly contagious disease, which causes diarrhea and vomiting among other symptoms, and often leads to death.
How does a dog become infected with Parvovirus?
Canine Parvovirus is, of course, a virus. The main source of this virus is the feces of infected dogs. The stool of an affected dog can have a high concentration of viral particles, which are highly resistant to heat, detergents, and alcohol. Therefore, due to its stability, CPV is easily transmitted via the hair or feet of infected dogs, contaminated shoes, clothes and other objects. Animals then ingest the virus, becoming infected. Subsequently, the virus is carried to the intestine where it invades the intestinal wall, causing inflammation. Dogs that are infected will usually become ill 7-10 days from the initial infection.
How does this disease affect the dog?
The clinical signs of CPV are somewhat variable, but generally take the form of severe vomiting and diarrhea. First, the virus infects a dog’s lymph nodes, thymus and tonsils. From there it spreads to the bloodstream. In puppies younger than 8 weeks old, it invades the rapidly growing heart cells, which can cause heart failure and death. In puppies older than 6 weeks, the virus spreads to the intestinal and bone marrow cells, causing intestinal disease (vomiting, diarrhea) and low white blood cell counts. Usually the vomiting starts first, followed by diarrhea, which is often bloody and quite foul-smelling. The dog will refuse food and water, and its temperature can either be low (below 101.5) or above 103. A dog showing these symptoms should be seen by a veterinarian as soon as possible.
How is it diagnosed?
When you bring your dog in with these symptoms, your veterinarian will examine the dog, and may want to do blood and fecal testing to aid in diagnosis. The first step is to rule out other possible causes of vomiting and diarrhea. A positive confirmation of CPV requires a stool test that identifies the virus is present, or a blood test that confirms antibodies to the CPV in the bloodstream. Occasionally, a dog with CPV will test negative on the fecal test so treatment may be recommended despite laboratory findings.
Can it be treated successfully?
There is no treatment to kill the virus once it infects the dog. However, supportive treatment, frequently including hospitalization, is essential in increasing the dog’s chance at survival. For example, until the disease runs its course, the dog will not be able to digest food properly and may need to be hospitalized. Also, he may need intravenous (IV) fluids to restore electrolyte balance and prevent dehydration from the vomiting and diarrhea. The veterinarian will also give injectable antibiotics to prevent secondary infection and blood tests will be needed to monitor progress. Recovery takes several days, and is usually complete when the dog is able to hold down food and has regular stools. Unfortunately, a few dogs can be so severely affected that they will not recover despite proper, aggressive treatment from a veterinarian.
Can it be prevented?
The best method of protecting your dog against CPV is proper vaccination. Puppies receive a parvo vaccination as part of their booster series given at 8,12 and 16 weeks of age. In some situations, the veterinarian may recommend an additional booster at 18-20 weeks of age. This is common with Rottweilers, as they have a natural immunity to the vaccine, and are at greater risk of infection. Yearly vaccination is essential after the series is completed in order to protect your dog adequately.
Is there a way to kill the virus in the environment?
It is of vital importance to properly disinfect contaminated areas, as the virus is capable of surviving in the environment for many months or even years. CVP can be killed on household and kennel surfaces by a 1:30 dilution of chlorine bleach, but it is impossible to kill in the yard, which further supports the need for regular vaccinations by your veterinarian. It is important to always use chlorine bleach as other virucidal agents will NOT kill CPV. Also, once a dog has recovered from CPV, he is still able to spread the virus through his stools for up to a month, so proper disinfection and prompt disposal of stools in the yard is very important.
Does Parvovirus pose a health risk for me? How about for my cats?
Presently, there is no evidence to indicate that CPV is transmittable to cats or humans.