The Feline Immunodeficiency Virus (FIV) virus reduces a cat’s immune system, slowly, over several years, Leaving affected cats more vulnerable to other feline infections later in life. FIV is not, on its own, a life threatening disease.
FIV is a cats-only disease. It CANNOT be transmitted to humans
Disease Information Sites
FIV Cats has a comprehensive site on FIV.
FIV Therapy has information about FIV and about a lot of the secondary conditions that occur with FIV.
FIV-HealthSicence Help & Support Group appears to be an active group supporting owners of FIV+ cats.
There’s a support group / forum from the FIV Therapy website too.