Feline immunodeficiency virus (FIV) is a virus that affects cats worldwide, with 2.5% to 4.4% of felines being infected. FIV attacks the immune system of infected cats, leaving them vulnerable to many other infections. The virus works by killing or damaging cells in a cats immune system, often targeting white blood cells, which eventually leads to a weakening of the immune system. FIV-positive cats may have the virus in their system for years before showing signs of illness. FIV is diagnosed through blood tests that detect antibodies to the virus. The most common way that FIV spreads among cats is through biting, and a mother cat infected with the virus can pass it to her kittens. However, FIV is not contagious through social grooming, sneezing, or sharing a litter box.

Symptoms of FIV in cats can include chronic or recurrent infections in the eyes, skin, upper respiratory tract, or bladder, constant diarrhea, persistent eye problems, seizures, behavioral changes, and signs of neurological disorders. Many felines infected with the illness end up developing some form of cancer or blood disease. Vigilance and close monitoring of the health and behavior of FIV-infected cats is important, and prompt evaluation and treatment is necessary when any signs of illness occur. FIV-positive cats may require longer or more intense treatments and courses of antibiotics than cats without FIV.

It is important to note that being FIV-positive is not the same as having feline AIDS (acquired immunodeficiency syndrome of cats). The FIV screening test detects antibodies that have been formed in a cats blood because of infection with the virus. An FIV-positive diagnosis means that a cat has been infected by the virus, but it may be years, if ever, before the cat develops the clinical signs referred to as feline AIDS.

In summary, FIV is a virus that attacks the immune system of cats, leaving them vulnerable to many other infections. It is diagnosed through blood tests that detect antibodies to the virus, and it is not contagious through social grooming, sneezing, or sharing a litter box. Vigilance and close monitoring of the health and behavior of FIV-infected cats is important, and prompt evaluation and treatment is necessary when any signs of illness occur.