Rabies primarily attacks the nervous system and causes an encephalitis. The virus is transmitted in saliva from the bite of an infected animal. The incubation period prior to clinical signs is extremely variable, but is usually two-to-eight weeks. The virus will begin shedding in saliva a short time before clinical signs develop, usually less than 10 days.
For both humans and domestic animals, the primary source of rabies is the bite of a rabid wild animal. The most common of these are skunk, raccoon, bat, and fox. Currently, the number of cats infected with rabies has surpassed that of dogs. The main reasons are that there are now more cats than dogs and cats tend to roam more often.
Clinical signsThere are three phases to the course of the disease: prodromal, furious, and paralytic. Death occurs three to-seven days from the onset of signs.
The prodomal stage lasts two-to-three days. The signs can include behavioral changes, fever, slow eye reflexes, and chewing at the bite site.
The furious stage lasts two-to-four days. During this stage, signs of erratic behavior may include irritability, restlessness, barking, aggression, vicious attacks on inanimate objects, and unexplained roaming. Disorientation and seizures may also develop.
The paralytic stage lasts two-to-four days, during which signs of paralysis develop, usually beginning in the limb that was bitten. Paralysis of the throat and face cause a change in the bark, drooling with typical foaming at the mouth, and a dropped jaw. These signs are followed by depression, coma, and death from respiratory paralysis.
Once clinical signs develop, there is no treatment.
Prevention in petsAll dogs and cats should be vaccinated against rabies according to local rules and regulations. Wild animals kept as pets should never be vaccinated, and contact with wild animals should be avoided. The recommendations for a pet bitten by a wild animal or a known rabid animal are as follows:
If the pet has been vaccinated, re-vaccinate and quarantine for 90 days.
If the pet has not been vaccinated, euthanize and submit tissue for rabies testing. If the owner is unwilling to euthanize the pet, it should be strictly quarantined for six months with vaccination one month prior to release.
As strict as this protocol sounds, it is the proper procedure to ensure that no one else is infected with this deadly disease.
Prevention in peoplePeople should also avoid wild animal contact. A skunk, raccoon, or fox walking down the street in broad daylight is not out to play; obviously the animal is sick and rabies should be the first disease on the list of possibilities.
If a person is bitten by an animal that is healthy and properly vaccinated, the animal must be quarantined for 10 days. If the bite is from a wild animal, it should be euthanized and submitted for testing. Unfortunately, the wild animal often escapes and cannot be tested.
If escape occurs, a physician should decide if the victim should undergo post-exposure prophylaxis. Rabies post-exposure vaccines are given on days zero, three, seven, 14, and 28 following the bite.
It is critical to keep pets vaccinated against this disease. Please contact your local veterinarian or health department for vaccine protocols. Some areas require annual vaccination, while others allow a three-year vaccine. Recent outbreaks of rabies in Texas and Florida point to the need for prevention. This is one disease we can and must control.
Editor's note: There is no state law for rabies vaccination in Ohio, but each county health department sets local rules. Some counties require that both cats and dogs be immunized, while others mandate only for dogs. Although cases of rabies are few and far between, the disease is serious enough that immunization is highly recommended.
More information on rabies is available at The Department of Rabies at the Pasteur Institute. Follow the link to the English version, if desired.
James T. Middendorf, DVM