Common feline illnesses include the following:

Upper respiratory infections (URIs). URIs are similar in many ways to the common cold in humans and produce many of the same symptoms: sneezing, runny nose and eyes, reddened eyes, fever, and decreased appetite. However, URIs can be much more serious than common colds¡ªthey can be fatal if left untreated. These airborne viruses are highly contagious; they can be transmitted to cats through human handling and through contact with other cats and with inanimate objects such as litter boxes, food bowls, and grooming tools. Separate any new cat from your other cats for at least three weeks until you are sure your newcomer doesn't have any symptoms of a URI.

Prevention is the best approach to URIs¡ªhave your cat vaccinated. But if your cat does come down with cold-like symptoms, contact your veterinarian right away. The veterinarian will probably prescribe antibiotics to prevent secondary infections and give you precise care instructions. Follow them carefully and make sure your cat eats and drinks sufficiently.

Rabies. All cats, even indoor cats, should be vaccinated against rabies, which is now seen more commonly in cats than in any other domestic animal. Rabies is a viral illness that is transmitted through bite wounds from infected animals and attacks the nervous system. If your cat bites anyone, you may need to show proof of rabies vaccination.

Rabies is a fatal illness. Prevent rabies through vaccination and by keeping your cat inside.

Feline panleukopenia. Commonly known as feline distemper, this is a highly contagious viral disease that can be transmitted through contact with humans, infected cats, clothing, hair, paws, food bowls, and even cat carriers. The disease comes on suddenly with vomiting, loss of appetite, and diarrhea. Vaccinate against this virus.

Feline leukemia virus (FeLV). FeLV is a fatal infectious virus that affects the immune system and can cause several forms of cancer and other associated diseases. It is transmitted through the saliva, urine, and feces of infected cats. There is no link between feline leukemia and human forms of leukemia.

There are blood tests to determine if your cat may be carrying the virus. Your cat should be tested before being vaccinated. Since there is no cure, it is best to keep your cat indoors (and away from contact with other cats). Discuss vaccination schedules with you veterinarian.

Feline immunodeficiency virus (FIV). FIV is similar to human acquired immune deficiency syndrome (AIDS), but it is not the same virus and cannot be passed to humans.

This fatal virus attacks the immune system, causing a variety of symptoms. General signs can include chronic, nonresponding infections; respiratory problems; appetite loss; persistent diarrhea; and severe oral infections. FIV is passed from cat to cat primarily through bites.

A vaccine is available to help protect cats from contracting FIV, but an FIV blood test should always be performed before vaccination. The best protection against FIV is keeping your cat happy indoors.

Feline infectious peritonitis (FIP). FIP is another virus that is almost always fatal to cats. This virus can take two forms, commonly referred to as wet (which involves fluid in the abdomen) and dry (which does not). Both forms of FIP may cause fever, lethargy, vomiting, diarrhea, and loss of appetite.

A blood test is available to determine if your cat has been exposed to this family of viruses. You can learn more about this test by talking to your regular veterinarian. There is no effective treatment for FIP, but there is hope for prevention in the form of recently developed vaccines. The best prevention is to keep your cat indoors, up-to-date on vaccines, and away from strange animals.