Parvo is an extremely contagious disease caused by the canine parvovirus type 2, or CPV-2.
Though parvo infections sometimes cause no symptoms in older dogs, the consequences in unvaccinated pups often are more severe and in many cases, fatal. Knowing the symptoms of a parvo infection, and the measures you can take to prevent one, will help you and your dog enjoy good health for years to come.
The canine parvovirus was discovered when it was identified as the culprit behind a 1978 epidemic of severe intestinal hemorrhaging in dogs. Subsequent research suggests that the virus first appeared around 1976, as a mutation of a virus that affected other animals.
The parvovirus spreads through oral-fecal contact. When a dog is infected, the virus takes up residence in the intestinal tract and contaminates the feces. Once exposed to the outside world, the viral cells are extremely hard to get rid of and easily can survive more than five months in the environment. The virus resists many household cleaners and detergents, which is one reason why it's so contagious.
The parvovirus attacks parts of the body where there are actively dividing cells especially the intestinal tract, thymus, bone marrow and lymph nodes.
Most of the symptoms of parvo are associated with its effect on the intestinal tract. It damages the intestinal lining that absorbs the nutrients from food, and causes an inflammatory response that further worsens digestive function. This can quickly lead to:
The other likely targets of the parvovirus the thymus, bone marrow and lymph nodes all play a role in the dog's immune system, and there is speculation that the parvovirus's effect on the immune system can make the dog more susceptible to other infections, though this has not been proven.
There is a rare form of the parvovirus infection that leads to heart failure in puppies, usually causing sudden death without any apparent symptoms.
When a puppy is extremely young under two weeks old the cardiac cells are still actively dividing, making the heart an attractive target for the parvovirus. This type of infection usually causes heart failure sometime after the pup is three to eight weeks old.
Most infections of this type occur when a non-immune bitch is infected late in her pregnancy and spreads the infection to her pups either in the uterus or shortly after birth. This kind of infection is rare since most dogs of breeding age are already immune to the virus through vaccination or prior exposure.
Currently no drug can directly combat the parvovirus. But it's important to get veterinary treatment if a dog has severe parvo symptoms treatment can accelerate recovery, and more importantly, prevent the potentially serious complications associated with parvo.
A veterinarian will perform a physical exam and consider the dog's age and symptoms before diagnosing a parvovirus infection. There also are lab tests that can identify signs of the virus in the blood or stool.
Because diarrhea leads to severe dehydration, treatment of parvo involves intravenous fluids, often containing electrolytes and other supplements. Anti-nausea drugs can help control vomiting, although an intravenous sugar and vitamin solution may still be necessary to meet the dog's nutritional needs.
Antibiotics also are usually given to prevent septicemia a potentially deadly complication to which dogs with parvovirus infections are particularly susceptible. It occurs when harmful bacteria begin to flourish in the embattled intestinal tract and then move into the blood stream, and it can lead to organ failure and death.
The best preventative measure to take against the parvovirus is to start immunization at a young age and keep the dogs vaccines current. The parvovirus vaccine is included in the series of vaccinations normally given to pups, and a yearly booster is also needed.
Because the virus is so highly contagious, it's important to minimize exposure to the virus. All dogs should be kept away from other dogs that have or have recently had the parvovirus. Puppies should be kept away from other dogs until their series of vaccinations is complete.
Most household cleaners and detergents cannot kill parvovirus in the environment, but chlorine bleach is effective in a 30-to-1 dilution.