Parvo 2

Pet Tales
by Barry B. Burtis D.V.M.

George's Story

It was now the beginning of day two of hospitalization for little George, not yet 72 hours since his owners had first noticed him unwell. George is the "cute as a button", 11 week old, black Pug puppy whose story I began to relate in my last column. He had just tested positive for parvovirus. Veterinarians try to remain optimistic and focus on the knowledge there is much we can do to help patients with this disease. Still, it is a sobering, formidable diagnosis to confront. We know there is much to do as we try to help the sick pet and worried owners understand what is happening. Sadly, not all endings are happy ones. The next few days, for George, would be very critical.

It is now almost 30 years since canine parvovirus infection first occurred in 1978. The virus did not exist before that time. It is believed that this is a disease caused by a virus of the cat or some other animal that adapted itself to be able to infect dogs. Suddenly then, within weeks, the disease had spread around the world and dogs were dying from it on every continent. As we hear about SARS, Ebola virus and Avian influenza the parvo story provides a terrifying example of the threat such diseases pose in our world.

I can still vividly recall the difficulty of dealing with the outbreak of a brand new disease.  When it first emerged, dogs of all ages could be infected. However, then, as it remains to this day, puppies were most at risk. For some time it seemed that every week brought in new cases of this dreaded disease. Veterinarians were trying to learn the cause of this epidemic of illness, what we could do to best treat dogs affected with the disease and if there was any way to prevent other dogs from developing it. It is certainly my hope that neither dogs nor any other animal species, including humans, have to go through such an experience in the future.

Today, we know the best approach to dealing with parvo is the prevention of the disease in the first place. Vaccination has been able to drastically reduce the incidence of the disease. Modified live virus vaccines are recommended for best protection. It is recommended that puppies be vaccinated, minimally, at 6, 9 and 12 weeks of age.  Interference from maternal antibody is the main reason for vaccine failure. This happens when a mother who has protection against the virus, in the form of antibodies, herself, passes this protection on to her puppies.  This protection in the puppy will run out when it is between 6 - 18 weeks old. If mom's protection is still present when it is vaccinated, it can interfere with the puppy developing long lasting protection of its own.  For this reason, some veterinarians recommend the initial vaccine protocol be extended until 22 weeks of age, especially for high risk breeds to develop parvo.  Rottweilers, Doberman pinschers, pit bulls, Labrador retrievers, German shepherds, English springer spaniels and Alaskan sled dogs are considered such breeds.

It is not known for certain but maternal antibody interference may have been the reason that even though George had received two vaccines before he became ill, he still fell victim to the disease.

There are certain hallmarks in current recommended treatments for individuals with parvovirus infection. Hospitalization for intensive therapy and supportive care will improve survival. Nursing care will be of utmost importance. Intravenous fluid therapy is the mainstay of treatment. The activity of affected puppies should be restricted. Attention to diet is critical. Food and water may need to be withheld to control prolonged vomiting. Special diets to provide nutritious, bland, easily digestible food should be used as feeding is gradually introduced to the recovering patient. Vigilant observation for any complications of the disease, are important. Finally, a number of medications may be necessary. These would include drugs to control vomiting and to relieve nausea, antibiotics to combat bacterial infection, analgesics to control pain, and anthelmintics to treat parasites.

George was hospitalized for 4 days as he was treated for his infection. He was a brave, well-behaved, charming little fellow. It was indeed a happy day for all concerned when he greeted his owners with jubilant face licks and wiggled his little bottom out the door, homeward bound again. A few more days of attentive care at home and then everyone  relaxed, knowing George had won his battle with parvovirus.