It’s Parvo time again!

Don’t let your dog be a victim

Imagine that a previously unknown and highly lethal virus began spreading through the population. The body has no natural immunity to the virus, and those infected with it almost always die. No one knows how it is transmitted, and as with all viruses, there is no cure. Researchers work feverishly to isolate the virus and develop a vaccine as the death toll rises. It sounds like the plot of a suspense novel, but that is exactly what happened in the late 1970’s when canine parvovirus shook the dog world.

Three decades later, Parvo is still a threat to the dog population, especially to puppies. A vaccine was developed and is now routinely given to dogs as part of their annual shots, but the vaccine must be given in a series of shots administered over a period of weeks. If the entire series of shots is not given, the vaccine will not be effective. Vets are better able to treat the disease today, and a dog that does acquire parvo has a good chance of survival if treatment is begun quickly. If a dog survives a parvo attack, it has a permanent immunity.

Puppies are especially susceptible to parvo due to a gap that opens in their immunity. If a puppy is born to a mother who has been vaccinated against parvo, or who has contracted and survived the disease, the puppy will obtain a temporary immunity from its mother’s milk. These maternal antibodies will decline over the first three months of a puppy’s life to a level at which they will not offer protection, but at which they are still high enough to interfere with the vaccine. It is during this time, when the maternal antibodies are too low to provide immunity, but high enough to prevent antibodies in response to the vaccine from forming, that the puppy is most at risk.

Parvo attacks a dog’s body in a number of ways. It begins by attacking the most rapidly dividing cells - the bone marrow, which leads to a suppression of the formation of infection fighting white blood cells, and the cells lining the intestinal wall. Vomiting and diarrhea lead to rapid dehydration and an imbalance in electrolytes, which affects cell function. Meanwhile, the intestines lose there ability to contain the natural digestive bacteria which reside there. These bacteria enter the bloodstream, which now has a depleted supply of white blood cells, and travels throughout the dogs body, causing secondary infections. Even with medical intervention this is a life threatening situation.

Since veterinarians cannot kill the parvo virus, they must treat the various symptoms. Fluids are administered to re-hydrate the dog and restore electrolyte balance. Antibiotics are given to fight the infections, medications are given to reduce vomiting and diarrhea, and sometimes blood transfusions are needed if the dog is anemic. It is really a balancing act, trying to keep the dog alive while its body fights the disease that is attacking it. If the dog survives, it will have a lifetime immunity, but it will take time – 3-4 days and sometimes a week – and it will be expensive. The dog will require round the clock care during the time it is being treated.

Prevention seems the better option. Parvovirus is transmitted through the feces of infected animals. The virus is very hardy and can survive for up to six months in the environment. If a puppy ingests the virus, by stepping in it and licking its paw, by sticking its nose in it, or by eating it, the pup will be infected. There is a natural impulse among people with new puppies to take them out and show them off and let them meet other dogs. This is the last thing you should do. Parks and other popular dog walking areas, as well as pet stores, are all potential hazards for a puppy with an incomplete immune system. Socialization is important for puppies and dogs, but do it in a safe place with dogs you know to be disease free. Until the vaccine series is complete, these areas should be avoided. Your vet will let you know when it is safe to expand your puppy’s circle of friends.