what is fiv?
Feline immunodeficiency virus (FIV) is a type of virus called a retrovirus. It is in the same family as feline leukemia virus (FeLV) and human immunodeficiency virus (HIV, the virus that causes AIDS). It attacks the immune system, and as a result, the cat is unable to fight off various infections and cancers. Approximately 2.5% of cats in the United States are infected with FIV.