After three recent cases in which animals tested positive for rabies, St. Mary's County Health Department officials reminded residents about the threat of rabies exposure and the importance of vaccinating their pets.

The cases involved three dogs bitten by wild animals carrying the disease. One dog was bitten by a raccoon and the two others by foxes.

In each case, the pet owner turned over the wild animal to the Health Department for testing. One dog had a current vaccination but was still required to complete a 45-day quarantine period in the family home. The other dogs were not vaccinated, and the Health Department said the owners voluntarily euthanized them rather than subject them to more severe quarantine requirements or the likelihood of developing rabies.

To protect pets and people from rabies, the Health Department recommends these measures:

* Be sure rabies vaccinations are up to date. In St. Mary's County, all cats and dogs at least 4 months old must be vaccinated. The vaccine protects pets that are more than a year old for three years. Rabies shot clinics are held monthly at the St. Mary's County Fairgrounds. Call the Animal Welfare League at 301-373-5659 for information.

* Keep pets in your home or yard, and walk them on a leash. County law requires all dogs to be leashed off their owner's property.

* Teach children to avoid wild animals or unfamiliar pets. Rabies is most likely to be carried by raccoons, foxes, skunks and bats; however, cats, dogs and farm animals that have not been vaccinated can also carry the disease.

* Do not feed pets outdoors. Pet food and other food sources such as unsecured garbage cans may attract unhealthy animals.

A wild animal that bites a domestic animal is presumed to be a carrier. If the wild animal is not collected and tested, or if it tests positive for rabies, the domestic animal by law must undergo a 45-day quarantine. In such situations, the requirement applies even if the domestic animal's vaccination is current. An unvaccinated pet must be quarantined for six months to ensure that the animal does not infect humans if it contracts the disease. The only alternative to the longer quarantine is to have the pet euthanized.

Rabies is a viral disease spread most often when saliva from a rabid animal enters a fresh cut or open wound. The disease attacks the nervous system, causing paralysis and almost certain death once symptoms appear. Symptoms usually develop within two to eight weeks after infection but can appear as soon as five days after.