Feline immunodeficiency virus (FIV) is a virus specific to the cat family. It is similar to HIV (human immunodeficiency virus, the cause of AIDS in people) in that it attacks and weakens the immune system and there is no cure. FIV was first recognized in the mid-1980s and has been found in cats worldwide. It is a species specific virus that harms only cats, and poses no risk to humans or other animals.