At the Animal Clinic at Thorndale, we diagnosed a case of rabies in a young kitten. It was a frightening experience for the kitten’s owners and very concerning for all the members of our staff who had come in contact with the kitten. Fortunately, our veterinary staff is pre-vaccinated against rabies and received booster vaccinations. The family members were treated for exposure. Treatments for humans are successful if begun prior to any signs of the disease appearing. Once the signs of the disease appear in animals or humans, survival is rare. We were fortunate that we identified rabies as the cause of this kitten’s illness and the family was able to seek immediate treatment.
Rabies is a viral disease that may infect any warm-blooded animal. Regardless of the initial site of virus introduction into the animal, the virus eventually invades the central nervous system. With rare exception, it is a uniformly fatal disease.
In the state of Pennsylvania, ALL dogs and cats are required to be vaccinated against rabies. The only exception is barn cats with minimal contact with humans. Of course, these cats are at greater risk of contacting wild animals carrying the disease and should be handled with caution.
Contributing Factors
For domestic pets, such as cats and dogs, the greatest risk factor for contracting rabies comes from failing to receive proper rabies immunization and then coming in contact with a rabid animal. In Chester County, the majority of rabies is carried by bats, raccoons and skunks. But it is important to realize that any warm blood animal can have the disease.
Prevalence
Rabies is found on a worldwide basis. Even though all warm-blooded animals can become infected, some species are more susceptible than others. Skunks, raccoons, and bats are considered most susceptible, while cats, dogs, horses, and humans have intermediate susceptibility. Opossums and birds are relatively more resistant to the virus compared to other species. It is important to note that while wildlife represents the major reservoir of rabies in nature; cats and dogs are the principal source for rabies transmission to humans.
Causes/Transmission
The usual source of rabies infection is the bite of an animal infected with the virus. The virus is found in high concentrations within saliva. Once inoculated into the victim, the virus travels up nerve endings to the central nervous system. Care must be taken when cleaning bite wounds on pets. The virus may be active in the saliva in the wound. Cut and nicks on hands, or splashing virally infected liquids into the eye have the possibility of transmitting the disease. There have been a few rare cases of humans contracting rabies by inhaling aerosolized virus in bat caves.
Clinical Signs
Rabies is classically divided into three distinct stages: prodromal, furious, and paralytic.
- The prodromal stage lasts 2-3 days and is characterized by major behavior changes. Normally friendly domestic animals, such as dogs and cats, become aggressive. In contrast, wildlife will lose the normal fear of humans. Also, wild animals which are normally seen only at night (nocturnal species) may be seen during the day.
- During the furious stage, cats will typically become very vicious and lunge at any moving object. They may have muscle tremors and incoordination. No all ill animals become vicious.
- During the final stage, the paralytic stage, paralysis sets in and death follows. Most cats die from rabies within 2-7 days after they begin to show signs of the disease.
Diagnosis
Rabies can be suspected based on clinical signs, but it can only be confirmed by microscopic examination of brain tissue. For this reason, animals suspected of having rabies are usually autopsied and a sample of brain tissue is submitted to a pathologist. Although this can be upsetting for owners, remember that there is no room for error with rabies. If a human has been exposed and does not receive treatment, death is inevitable.
Rabies Quarantine
Whenever a pet animal bites a human, the animal is usually required to be confined and observed by a veterinarian for at least a 10 day period. If a cat or dog has been bitten by an unvaccinated or wild animal, and the victim’s rabies vaccination is not up to date, the pet which was bitten will either be humanly destroyed or undergo a strict 6 month quarantine, ideally under veterinary supervision. From the time the virus enters the bite victim’s tissues until the victim begins to show signs of the disease and becomes infective is generally thought to occur within 6 months. There was a reported case of a cat developing rabies 7 years after exposure to a rabid bat. Dog and cat victims of bite wounds of unknown origin are immediately vaccinated against rabies, even if they have received a rabies vaccine before.
Treatment
Treatment is not recommended for animals with rabies because of the potential risk for human exposure to the virus. In addition, no successful treatment has been found.
Prognosis
Rabies is always fatal in warm-blooded animals that develop the disease.
Transmission to Humans
Rabies can be transmitted to a human through the bite of an infected animal or inoculation of rabies-infected saliva into an open wound. Whenever an animal bites a human, a physician should always be contacted promptly. In some areas, physicians are required to contact local animal control officials so that the vaccination status of the animal can be verified and an appropriate quarantine initiated.
Prevention
Because rabies-immunized pets represent an important buffer between humans and the rabies reservoir found in wildlife, the importance of regular rabies boosters for pets cannot be overemphasized.
The first rabies vaccine is usually given at 12-16 weeks of age, followed by regular boosters. All pets will need a booster one year after the original vaccination, regardless of the type of vaccine used. Thereafter, depending upon local regulations and the type of vaccine being used, the boosters are given every year or every three years. These vaccines are considered safe and effective. In Pennsylvania, they are required by state law.
To learn more about rabies in Chester County follow this link to our health department.