by Amanda L. Maus DVM
Feline Immunodeficiency Virus (FIV), also called Feline AIDS, is a virus that is very similar to the HIV that causes human AIDS. FIV is an uncommon disease that is most likely to be transmitted through bite wounds from fighting. Outdoor, unneutered male cats are at the highest risk. FIV can also be transmitted through sexual activity. FIV can be passed from a queen (momma cat) to her kittens during pregnancy and through nursing. FIV is not as contagious as Feline Leukemia Virus (FeLV) and is not as aggressive as FeLV.
FIV affects the immune system, specifically causing a decrease in a type of white blood cell called a lymphocyte. For days or a few weeks after infection, the cat may show signs of lethargy, decreased appetite, mouth infection, eye infection, respiratory infection, diarrhea, or no symptoms at all. Some cats have FIV for years or an entire lifetime without developing any of the above symptoms or just mild symptoms. Similar to FeLV, FIV cats are prone to developing a type of cancer called lymphoma. FIV can also affect the brain, causing changes in behavior, seizures, and abnormal walking or weakness. Cats with FIV are prone to other infections since their immune system cannot effectively fight infections.
A very sensitive screening test for FIV can be performed in your veterinarian's office. Most cats are positive for antibodies on the test within 2 months of exposure. If your cat is positive, your veterinarian may recommend a confirmation test that needs sent to laboratory. Positive kittens should be retested at 6 months of age since the antibodies detected on the positive test may be from the queen. All newly adopted cats should be tested to determine their FIV status. Cats who spend time outdoors around other cats should be retested yearly.
Cats with FIV need to be closely monitored for signs of illness and infection. Infections need treated promptly before they become serious. Keeping a FIV positive cat indoors helps prevent the spread of the FIV infection to other cats and helps decrease the exposure of the FIV positive cat to other infections. There is a low risk of FIV spreading between cats in the same household unless there is fighting.
Prevention of this disease is easily accomplished by keeping your cat indoors only. A FIV vaccine is available but has several drawbacks. First, the antibodies produced by the vaccine cannot be distinguished from the antibodies produced by infected cats on the blood test for FIV. Second, the vaccine does not protect against all of the strains of FIV.
FIV is used as a model for understanding HIV in humans. Research is being done at institutions such as the veterinary college at North Carolina State University to help figure out how FIV is able to affect the immune system and to develop new vaccines.
On the PAWSitively CATS website, you can become a sponsor of a cat with FIV or consider adoption of a cat with FIV.