Feline AIDS

The term “AIDS” conjures up a host of frightening thoughts for the cat owner. I get questions from my clients all the time about how their cat can contract AIDS, and if they can get it from them. Well, to be brief, cats contract AIDS the same way humans do (for the most part), and humans cannot get the feline form. But when am I ever brief?

Feline AIDS is caused by Feline Immunodeficiency Virus (FIV). Although this virus is closely related to HIV, it isn’t infectious to humans, nor is HIV to cats. Most cats get FIV from blood-to-blood or sexual contact with an infected cat. This is usually done by fighting or breeding (there aren’t a whole lot of IV drug-users in the cat world). Unlike HIV, FIV is often present in high levels in the saliva of infected cats. Occasionally an infected queen will spread the virus to her kittens in the womb, but this is actually fairly uncommon. Cats can carry the virus for many years before becoming clinical with the disease. The average length of time is 5 years, although I just had to put down a cat that has been FIV-positive for over 12 years, and just became symptomatic a few months ago.

The symptoms of FIV are similar to what HIV does to a human. It is an immunosuppressive virus that predisposes a cat to other infections. Symptoms include weight loss, unthrifty coat, anorexia, sores in the mouth, fever, lethargy and swollen lymph nodes. There is no cure for feline AIDS. All cats infected with FIV will eventually succumb to the virus, but there are medications that can help support an infected cat’s immune system and help fend off clinical disease. The one that has been used most frequently with the most success is alpha interferon. AZT, an anti-HIV drug, has been used in cats with clinical disease with some success, but it can cause anemia. Other anti-HIV drugs have been shown to be either toxic or ineffective in treating FIV in cats.

Diagnosis of FIV is done by a simple in-house blood test. If a cat tests positive, then a second test, called a Western Blot, may be sent to an outside lab to confirm the results. Testing is recommended for all new kittens and cats brought into a household, and all cats presented with the aforementioned symptoms. If your cat tests negative for FIV, then the best way to prevent the disease is to keep that cat indoors, away from other cats that can infect it. If you have an outdoor cat that you cannot keep confined, then the best way to prevent infection is spay or neuter it. Neutered cats aren’t breeding, and they are less likely to start fights, although they could still be on the receiving end of a battle.

For at-risk cats, a vaccine is also available. It has been shown in clinical trials to be 82% effective in the prevention of FIV. The major fallacy of the vaccine is that it will cause a vaccinated cat to test positive on an FIV test. For this reason, all cats that are to be vaccinated should be tested prior to vaccination. Three doses of the vaccine must be given initially at 3-4 week intervals, and then it should be boosted annually. Some veterinarians also recommend vaccination of cats that share the household with known FIV-positive cats. Realistically, the risk of transmission in this environment is quite low, unless the cats fight.

Cat owners should discuss the risk of FIV infection and the benefits of testing and vaccination with their veterinarian. If you have further questions about FIV, fell free to email me at hannondvm@msn.com.