Rabies

Dr. Eisenberg,

I recently adopted a dog that has had all his vaccinations except the rabies vaccine. I was told he would need this vaccine and that it had to be given by my vet. What is rabies? Does my dog really need this vaccination because I always worry about over vaccinating my pet?

A Rabid Fan

Dear Rabid Fan,

Rabies is a disease caused by a rhabdovirus and it has been one of the most feared infections throughout history. According to the Illinois Department of Public Health statistics reported for 2005 there were 51 positive cases of rabies documented in animals in Illinois. DuPage County reported 2 cases of rabies in bats. Although there were no reported case of rabies in dogs, cats, or humans, it was found in bats, cows, foxes, and skunks in Illinois. It is evident the virus is still present in the wildlife of Illinois and needs to be controlled.

The virus is present in an infected animal's saliva and is most often transmitted via a bite wound. Once inside the wound the virus attaches to muscle cells. It then penetrates the nervous tissue and slowly progresses to the brain tissue. Once the virus in inside the nervous system it cannot be attacked by the host?s immune system. This slow progression can take as long as one year but usually takes 20 to 30 days. Once inside the brain it proceeds to become segregated throughout the body, including the victim?s saliva. It is at this point the virus can again be transmitted to another victim and the symptoms of the virus become evident. These symptoms area called stages and they consist of the Prodromal, Excitative, and Paralytic or Dumb stage. This final stage is when the respiratory muscles become paralyzed and the animal soon dies. Most human exposure occurs during this final stage.

It is a state law in Illinois that all dogs be vaccinated against the rabies virus with an approved killed vaccine that must be given be a licensed veterinarian. The duration of the immunity may vary from one to three years depending on the vaccine used. Local laws govern other pets and their rabies requirements. In DuPage County, for example, all cats are required to be vaccinated with the rabies vaccine. For any dog or cat that is receiving the vaccine for the first time, a booster is required in one year. This booster can then be a one-year or three- year vaccine. The vaccines are safe and effective. Your veterinarian can further explain the benefits of the vaccine and alleviate any other concerns you may have.