September 28 is World Rabies Day. Although you may have vaccinated your pet against Rabies, you may not know how this virus is transmitted, or that this virus does affect humans as well. We hope that the information below shines a light on the importance of vaccinating pets against this fatal virus.
What is Rabies?
Rabies is a viral disease that can infect all warm-blooded animals, including dogs, cats and people, although some species are somewhat naturally resistant to the disease. When signs of rabies occur, it is an almost invariably fatal disease.
Rabies has been recognized and described since approximately 2300 BC.
How widespread is Rabies?
Rabies occurs in every continent except Australia and Antarctica. Most countries are affected, with the exception of a few island countries.
Here is a current list of rabies-free countries:
Antigua, Australia, Bahamas, Barbados, Bermuda, Cayman Islands, Fiji, Finland, Iceland, Ireland, Jamaica, Japan, New Zealand, Norway, St. Kitts-Nevis, Anguilla, St. Lucia, St. Martin, St. Pierre et Miquelon Islands, St Vincent, Sweden, Taiwan, Turks and Caicos Islands, United Kingdom, Uruguay.
These rabies-free countries have relied on strict quarantine laws to keep the disease out, and particularly to stop the virus getting into the wildlife of those countries. Great Britain and some other rabies-free countries have recently changed their quarantine regulations for fully vaccinated and microchip identifiable cats and dogs that meet certain conditions
How is the virus transmitted?
Rabies virus does not survive long outside a mammal’s body. The infection is transmitted when one infected animal bites another. In Europe, foxes are the main reservoir while in North America the skunk, fox, raccoon and bat are important sources of infection. In Asia, Africa and Latin America the main reservoir is not wildlife but stray dogs. In these areas, human infection and fatalities are more common.
How long is the incubation period?
The incubation period can vary from ten days to one year or longer. In dogs, the incubation period is typically two weeks to four months. Incubation in the cat is generally less than in the dog and is typically three to eight weeks. Death usually occurs within ten days from the first onset of signs. The speed at which clinical signs develop depends upon:
- The site of infection – the nearer the bite is to the brain and spinal cord, the quicker the virus reaches the nervous tissue
- The severity of the bite
- The amount of virus injected by the bite
What are the clinical signs?
Following a bite from a rabid animal, the disease progresses in stages; in the first or prodromal phase the pet undergoes a marked change in temperament. Quiet pets become agitated and active pets become nervous or shy.
Following this stage, there are two recognized forms of the clinical disease:
- Furious rabies occurs when the rabid dog becomes highly excitable and displays evidence of a depraved appetite, eating and chewing stones, earth and rubbish (pica). Paralysis eventually sets in and the rabid animal may be unable to eat and drink. Hydrophobia (fear of water) is not a sign of rabies in dogs. This is a feature of human rabies. The dog finally dies in a violent seizure.
- Dumb rabies is the more common form in dogs. There is progressive paralysis involving the limbs, distortion of the face and a similar difficulty in swallowing. Owners will frequently think the dog has something stuck in the mouth or throat. Care should be taken in examination since rabies may be transmitted by saliva. Ultimately the dog becomes comatose and dies.
Is it possible to survive a bite from a rabid animal?
There are isolated and poorly documented reports of both dogs and people surviving. In some cases, there may have been very little rabies virus present in the saliva at the time the rabid animal bit its victim. In this situation, the victim may not develop rabies.
However, as Louis Pasteur was the first to show, it is possible to interrupt the progression from an infected bite to the onset of signs by the early post-bite use of anti-rabies serum. This antiserum contains specific immune antibodies to the virus. The most important method for preventing the progression of rabies is by administering a dose of rabies vaccine. The vaccine stimulates the bitten animal to develop its own neutralizing antibodies to the rabies virus. Without vaccination and rapid post-exposure treatment, the chances of survival are poor.
Is vaccination effective?
Vaccination promotes the production of antibodies but is only effective if given before the virus enters the nervous system. Modern rabies vaccines for dogs, cats, horses and ferrets are extremely safe and effective.
What is the treatment for rabies?
There is no treatment for a dog with rabies. If rabies is suspected, the dog has to be kept in isolation and prevented from escaping or injuring someone. Your veterinarian is required by law to notify the local and state or provincial animal disease regulatory authorities. These authorities will determine the steps necessary to properly protect the public.
Can I catch rabies?
Yes, the disease is zoonotic or can be transmitted from an animal to man. It is only transmitted by the bite of a rabid animal. The virus is present in the saliva of the infected animal only for a limited time.
If any animal that may be suspicious for rabies bites you, immediately wash and flush the wound thoroughly with soap and water and seek immediate medical assistance.
Post exposure rabies treatment with serum or vaccine may be recommended and is very successful if begun quickly.
When should my pet be vaccinated?
There are several rabies vaccines approved for dogs, cats, horses and ferrets. All dogs and cats should be vaccinated at sixteen weeks of age. Generally in the United States and Canada, rabies vaccination is mandatory. Rabies re-vaccination boosters are also required, and the frequency of re-vaccination is dependent on state or provincial law. Your veterinarian will advise you on the appropriate re-vaccination intervals and can assist you in obtaining any necessary licenses for your pet.
This client information sheet is based on material written by: Ernest Ward, DVM
© Copyright 2009 Lifelearn Inc. Used and/or modified with permission under license.