Rabies in Dogs
Overview of Rabies in Dogs
For most people, hearing the word rabies strikes great fear. With Hollywood portrayals such as “Cujo,” and often lethal result of a rabies infection, these fears are somewhat justified. But with understanding and knowledge, fears can be replaced with a healthy respect for the virus.
The rabies virus can infect almost any mammal. It is shed in the saliva and transmitted typically by bite wounds. Without treatment, the virus eventually attacks the nervous system and results in death. Throughout the world, 35,000 people die each year from rabies. In the United States, about 3 people succumb each year to rabies.
In the United States, rabies is most commonly found in skunks, raccoons, foxes, coyotes and bats. Despite their bad rap, rabies in ferrets is quite uncommon. Since 1958, only 22 ferrets have been diagnosed with rabies.
Recently in the United States, cats have become the number one domestic animal diagnosed with rabies. It is suspected this is due to more cats being kept as pets and allowed to roam their neighborhoods.
Diagnosis of Rabies in Dogs
Diagnosing rabies can be difficult. In the early stages, the virus has not yet attacked the brain and the animal acts normally. There are no body changes and no test that can determine if an animal or person was exposed to the virus. Unfortunately, the only way to diagnose rabies is to examine brain tissue, and this can only be done after the animal is dead. This means that testing your pet for rabies is not a test he can survive. Euthanasia is required. For information of human testing of advanced rabies, consult your family physician.
Treatment of Rabies in Dogs
Rabies is a fatal virus and there is no treatment for those animals in the final stages of the disease. People exposed to rabies can receive injections to reduce the risk of rabies infection but these injections have not been extensively tested in animals. Due to the serious risk of transmission to humans, animals that have been bitten by another animal with confirmed rabies should be euthanized.
There is no home care for rabies. If your animal is showing the signs of rabies, euthanasia and testing is recommended. If your pet is euthanized or dies for reasons not related to rabies and has bitten someone within 10 days before his death, testing is required by law.
The best way to prevent rabies exposure is to have your pet appropriately vaccinated and reduce his risk of exposure to wildlife. This is done by keeping your cats indoor and your dogs confined or leash walked only. Allowing your pets to roam will only increase the risk of exposure to rabies.
In-depth information on Canine Rabies
Rabies virus is shed in the saliva of the infected animal. It is transmitted to another animal through bite wounds. After being bitten by a rabid animal, the virus slowly migrates up the nerves to the spinal cord. It then travels up the spinal cord to the brain. Once in the brain, the signs of rabies can be seen. Prior to reaching the brain, the animal will act normally and not be contagious. Once the virus reaches the brain, it spreads to the nearby salivary glands and is shed in the saliva.
When the virus begins to shed, studies have shown that the animal will die from the rabies infection within 10 days. The time it takes for the virus to reach to brain varies and is dependent on the placement of the bite wound. Average incubation lasts from 2-8 weeks. During the incubation period, the animal is NOT contagious.
When the virus finally arrives at the brain, signs of rabies are seen. There are typically 3 final phases of rabies Once these signs begin, death usually occurs within 10 days.
Prodromal Phase Subtle changes occur such as erratic behavior, fever or licking/chewing at the previous bite site.
Furious Phase: More erratic and unusual behavior is characteristic of this phase. You may notice irritability, inappropriate barking, restlessness, inappropriate aggression, eating abnormal and non food items, roaming, pacing, staggering, disorientation and even seizures.
Paralytic Phase This phase is considered the final phase. The rabid animal will become weak and the nerves to the throat no longer function. This results in inability to swallow. You will notice drooling and difficulty eating. The animal is not afraid of water; he/she just cannot swallow it so avoids it. Additionally, depression and coma may be seen just prior to death.
Not all rabid animals follow this pathway but all are dead within 10 days of the virus attacking the brain.
Rabies perpetuates because of the wild animal reservoirs. Foxes, raccoons, skunks, coyotes and bats have high rates of rabies infections and exposure to these animals is the primary way rabies is spread to our pets and us.
In human rabies, the current US cases have been associated with bat exposure. Bats have tiny sharp teeth. You may have been bitten but do not know and may not find any marks. Children and incapacitated people may be unable to tell if a bite occurred. Consult your physician immediately if:
- You were sleeping and woke to find a bat in your room.
- A bat is found in a room with an unattended child, mentally challenged individual or intoxicated person.
- If the bat is not available for testing, many physicians will recommend rabies exposure treatment.
If a person is bitten by an unvaccinated dog or cat, euthanasia and testing is recommended. Another alternative is to strictly isolate the animal for 6 months. If after 6 months no signs of rabies appear, the animal can be vaccinated and released.
If a person is bitten by a vaccinated dog or cat, the animal is observed for 10 days. If signs of rabies develop, the animal should be euthanized and tested for rabies.
The reason for the 10 day quarantine is that if the animal was shedding the virus when he/she bit the person, he/she will be dead from rabies within 10 days. If the animal appears normal after 10 days, then he/she was not shedding the virus at the time of the bite. It does not, however, mean the animal is free from rabies. The virus may not have reached the brain yet. (If this is the case, the animal was still not contagious when he/she bit the person).
Veterinary Care In-Depth
In-depth Information on Diagnosis of Canine Rabies
There is no reliable test that can be done on a live animal. Euthanasia is required for a confirmation of rabies. There are several methods available to detect the virus in brain tissue.
Direct fluorescent antibody test is the test of choice. It is a rapid and reliable test for rabies.
Previously, the brain tissue was examined under a microscope for characteristic signs of rabies infection. This test was found to be moderately reliable in dogs but unreliable in cats.
Other more extensive tests are being investigated.
In-depth Information on Treatment of Canine Rabies
There is no treatment for rabies. Almost every animal infected with rabies will die. Due to the serious potential for transmission to people, treatment should not be attempted and animals showing signs of rabies should be euthanized and tested for confirmation.
Contact your physician for human treatment guidelines and recommendations.
Every animal bite should be reported to your local rabies or animal control center.