FELINE IMMUNODEFICIENCY VIRUS (FIV)

Feline Immunodeficiency virus (FIV) is an infectious retrovirus that suppresses the cat’s immune system much like HIV affects people.  It is termed “Kitty Aids”.  This virus is contagious from cat-to-cat, but not to people or other animals.  By suppressing the cat’s immune system, this virus decreases the resistance of the cat to other diseases.

Transmission is through fighting, primarily bite wounds.  Intact (not neutered), outdoor male cats are at highest risk for FIV because they roam a larger territory and tend to fight more to protect their territory.  However, ANY cat is at risk for FIV infection.  It is estimated that up to 10% of the general (healthy) population and 10-20% of  “sick” cats may be infected with FIV virus.  It is also possible for a cat to be infected with both FeLV and FIV viruses.

Unlike Feline Leukemia, this virus is not transmitted from the mother cat to the kittens.  Any young kitten (less than 6 months) testing positive does not necessarily have the infection.  Maternal antibodies from the mother cat will cause a false positive.  When a kitten is tested positive, recommend re-testing in 2 months.  If the kitten is still positive then it is infected with FIV virus.

There are no signs specific for FIV infection.  The main effect of the virus is to disrupt the cat’s immune system.  The infection has two stages.  During the early phase the cat may appear healthy and owners may not notice any problems at all.  Common signs of stage 1 infection are: enlargement of lymph nodes, fever, poor coat condition, lethargy, and general unthriftiness.  Stage 1 may be anywhere from 2-6 months after infection.  The later phase (stage 2) occurs when the immune system starts to weaken.  The cat may then show signs such as loss of appetite, weight loss, diarrhea (persistent), dental disease and mouth sores (ulcers), and infections involving the skin, urinary tract, and upper respiratory system.  Stage 2 may not occur until months to years after the initial infection.  Unlike Feline Leukemia, in which some cats can throw off the infection, once a cat has contracted FIV it is permanently infected.

Diagnosis is made by clinical signs and a positive blood test.  Testing is recommended for cats at least 6 months of age, all stray cats, and ill cats.  Because of the incubation period, if a ‘suspicious’ cat showing clinical signs of FIV tests negative, recommend re-testing in 2 months.  Due to the high accuracy of the tests for feline immunodeficiency virus, a positive test is diagnostic for infection.  However, we do recommend re-testing the cat in 2 months to verify the infection.  For weak positive results it is recommended that laboratory tests such as IFA or Western Blot be performed to confirm the infection.

Cats at high risk are outdoor, intact male cats.  However, ANY outdoor cat is at risk because of the possibility of other cats starting fights.  There is NO VACCINE available to protect against this virus.  Only absolute isolation from other cats will protect your cat from contracting this virus.