Rabies is a viral disease that can affect all warm-blooded mammals, including dogs, cats, wildlife and humans. The virus infects cells of the nervous system, producing in coordination and behavioral abnormalities, such as unusual aggression or withdrawal. Once the signs of Rabies appear, the disease is always fatal. Rabies is usually transmitted by bite wounds, often from infected wildlife, which represent there largest reservoir of the disease in the U.S. Vaccines are very effective in preventing Rabies. Most states in the U.S. require vaccination of dogs at 1 to 3-year intervals. Many states also require Rabies vaccinations for cats.
What is rabies?
Rabies is a viral disease that can infect all warm-blooded animals, including
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 2300 BC.
How widespread
is rabies?
Rabies occurs on every continent except Australia and Antarctica. Most countries
are affected with the exception of a few island countries such as Great Britain,
Ireland, Japan and Hawaii. Norway, Sweden and the Iberian Peninsula are also
free of rabies.
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. Britain and some other rabies-free countries are gradually
relaxing quarantine regulations for fully vaccinated and microchip identifiable
cats and dogs, but only from certain countries.
How is the virus
transmitted?
Rabies virus does not survive long outside a mammal’s body. The virus
can be shed in the saliva of infected animals and bite wounds are the usual
means of transmission of infection. In North America the skunk, raccoon and
bat are important reservoirs whereas in Europe foxes are the main source of
infection for people and other animals. In Asia, Africa and Latin America the
main reservoir is not wildlife but stray, free-living dogs. In these areas infection
of man is more common.
How long is the
incubation period between a bite from an infected animal and the appearance
of symptoms?
This can vary from ten days to one year or longer. 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. Rabies virus is not always present
in saliva of an infected animal.
What are the clinical
signs of Rabies?
Following a bite or scratch from a rabid animal, the disease progresses in stages.
In the first or prodromal stage, there is a marked change in temperament; quiet
cats become agitated and can become aggressive, while active extroverts may
become nervous or shy.
This phase is then followed by so-called furious rabies that is by far the most common type in the cat. During this phase, excitement predominates and it is at this stage that the cat is most dangerous, both to other animals and to the owner. The cat becomes increasingly nervous, irritable and vicious. Muscle spasms will often prevent swallowing and there is excessive drooling of saliva.
The third stage is the paralytic stage, which usually occurs after about seven days. Ultimately the cat will become comatose and die.
A noted feature of the condition in cats is the widely dilated pupil throughout all stages of the disease.
How is Rabies diagnosed?
Rabies can only be diagnosed by direct examination of the brain. It is not possible
to diagnose this disease in a living animal. If there is a high suspicion that
the animal has rabies, or if an animal showing symptoms of rabies dies suddenly,
your veterinarian may recommend submission of the appropriate brain samples
for testing.
Is it possible
to survive a bite from a rabid animal?
In some cases, there is no rabies virus present in the saliva at the time the
rabid animal bites another. In this situation, the bitten animal will not develop
rabies. However, once the symptoms of rabies develop, the disease will almost
invariably progress to death. There are very rare and poorly documented cases
where people and animals have recovered. 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.
Is post-bite vaccination
always effective in people?
The anti-rabies antibodies produced by post-bite vaccination are only effective
if administered before the rabies virus enters the nervous system. Once in nerve
cells the virus spreads along the nerve fibers and is protected from the effects
of the antibody. Therefore the early use of vaccine is important in people that
are exposed, or probably exposed, to a rabid animal. Of course, for people that
are likely to be exposed to rabies because of their career ,such as veterinarians
and wildlife control officers, it is preferable to be vaccinated in advance.
Is post-bite vaccination used in exposed cats?
Because of the potential risk to people, an unvaccinated exposed cat should
not normally be given either antiserum or vaccine, because it may mask signs
of infection. If there is a high probability of exposure the safest policy is
to euthanize the animal; the alternative is strict quarantine for many months.
If the exposed cat has previously been vaccinated then a booster vaccination is indicated followed by a period of at least thirty days of quarantine and careful observation.
What is the treatment
for Rabies?
There is no treatment for a cat with rabies infection. If rabies is suspected
the cat has to be kept in isolation and prevented from escaping or injuring
someone. Your veterinarian is required by law to notify the animal disease regulatory
authorities.
Can I catch rabies?
Yes, the disease is zoonotic, meaning it can be transmitted from an animal to
man. However 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 you are bitten by any animal that may be rabid, you should immediately wash the wound thoroughly with soap and water and seek the advice of a doctor without delay. Suspicious animals include stray or feral dogs or cats and any wild animal, particularly if the animal is showing unusual behavior such as lack of fear of people, salivation, or aggression. Post-exposure rabies treatment with serum or vaccine may be recommended and is very successful if given immediately after exposure.
Should my cat be
vaccinated?
Yes. Rabies vaccination is required by law in many states and provinces. Rabies
vaccination of cats is important for your safety as well as your cats. Rabies
vaccines are very safe and effective. They are usually first given at three
to four months of age. Depending on your state’s laws and the advice of
your veterinarian, revaccination will be recommended at specific intervals.
Are there any ill
effects from rabies vaccination?
Rabies vaccines are very safe and there is no risk of the vaccine causing rabies.
The formation of lumps (sarcomas) has been associated with some vaccines including
rabies vaccines, but this is still unproven and controversial. These cases are
extremely rare. As with all vaccines, the individual cat may show some transient
mild side effects in the day or so following vaccination. These may include
some lethargy and inappetance. If your cat shows more pronounced signs including
difficulty in breathing this could indicate an allergic reaction to one or more
components of the vaccine and you should call your veterinarian at once.