Feline Immunodeficiency Virus (FIV) is an infectious viral disease that weakens the immune system of cats. FIV is passed from cat to cat through saliva/ blood transfer typically from bite wounds or mating.
Casual contact such as sharing food bowls or mutual grooming is not likely to spread the disease but in rare cases can happen.
Tom cats (mature, unneutered males) are often infected because of the frequent fighting and mating.
Diagnosis can be made with a simple blood test at most clinics.