The feline immunodeficiency virus or FIV is a very common infectious disease. It is estimated three percent of healthy cats in the U.S. and 14 percent of cats with health problems have the virus.
FIV is most prevalent in intact males that roam free outdoors and fight with other cats. Bites from infected cats are the primary mode of transmission. That’s why keeping your cat indoors is the best way to avoid the virus.
According to the NYDailyNews.com:
Feline AIDS works much like the human variety, weakening cats' immune system and making them susceptible to infections of the skin, eyes, nose, mouth and urinary tract as well as more serious ailments like cancer and kidney failure. The disease typically stays latent for years, with cats becoming ill later in life.
FIV is frequently confused with the feline leukemia virus (FeLV), which also attacks the immune system. But FeLV can be spread through casual contact between cats, and while cats with FIV can have normal life spans, those with FeLV often die within three years of becoming infected.