FIV is a retrovirus similar to the Human Immunodeficiency Virus (HIV also know as AIDS).  Feline Immunodeficiency Virus (FIV) is a viral infection that attacks the immune system of cats.  It is also know as Feline Acquired Immunodeficiency Syndrome (Feline AIDS).  The immunodeficiency caused by the virus can promote a variety of symptoms including: Infections, impaired immune responses, anemia’s, gum and mouth infections, some types of cancer, and neurologic disease (much like in Humans having this similar disease).