Feline immunodeficiency virus (FIV) is a cat-only virus that is seen in similar frequency to the feline leukemia virus (FeLV) (make FeLV a hyperlink to this page). FIV is commonly known as “Feline Aids” due to its similarity to the HIV virus in humans.
FIV is often referred to as the “Aggressive Cat Disease” (versus FeLV which is called the “Friendly Cat Disease”) due to its primary mode of transmission. Adult, male cats and other free roaming cats are at highest risk for contracting this virus because bite wounds are the most effective way of spreading FIV. Prolonged close contact is a much less common means of transfer.
When a cat is infected with the virus, their immune system can mount a strong enough response to decrease its replication but is unable to eliminate the virus from the body. FIV then melds itself into the cat’s DNA making it a permanent fixture in your cat’s body. Those infected with the virus can live several years before seeing any problems related to the virus. In fact, most of the time cats do not get sick from the virus itself, but from secondary infections as a result of the damage FIV has caused to their immune systems. Complications from these secondary infections may cause these cats to succumb to their illness.
We recommend testing all kittens by 12 weeks of age to know their FeLV/FIV status. Each kitten in a litter should be tested because it is not safe to assume if one is negative that the rest of the litter will be negative.
Cats that go outside, or cats that live with cats that go outside, are at highest risk for contracting this virus. We recommend testing them for FIV annually to make sure they have not become infected. For cats that are indoor-only and are not exposed to cats that go outdoors, we recommend testing every other year. We also recommend retesting any cats who are sick to make sure FIV is not the cause of the illness.
There is no effective treatment for FIV. Unfortunately, there is not even an effective vaccine that we feel comfortable recommending. It is best to just understand the risks to your cat and to prevent those risks as best as possible. Not allowing a lot of stray cats to roam around your house, neutering your male cats and/or keeping your cats indoors are ways to reduce the risk of exposing your cats to FIV.