Feline Immunodeficiency Virus (FIV) is a serious debilitating infectious disease in cats. It suppresses the immune system leaving infected cats vulnerable to opportunistic infections and increases the cats risk of developing cancer six-fold.

The course of disease is as follows: Six to eight weeks post-exposure the cat may have a fever, a decreased white blood cell count, and swollen glands. Since cats often mask disease, owners are often unaware that their cat is sick. After the cat recovers from the initial illness, he becomes an FIV carrier and generally remains assymptomatic for four to eight years. Eventually, the number of specific white blood cells (T-helper cells) decreases to the point where the cat can no longer fight off disease successfully and the cat suffers from opportunistic infections. This is called AIDS Related Complex (ARC). With proper care and treatment from your veterinarian, cats in the ARC stage of FIV may still live several years. Finally, the cat reaches the full-blown Autoimmune Deficiency Syndrome (AIDS) stage in which the immune system collapses and he becomes terminally ill.

FIV is transmitted only between cats, usually through bite wounds. In-utero infection is rare and FIV is not transmitted via casual contact, such as mutual grooming. Although FIV and HIV (the human AIDS virus) are very similar diseases, they are species-specific. Therefore FIV is not transmissible to humans and HIV is not transmissible to cats.

To ensure the safety of your cat, you must keep him inside and away from unfamiliar cats whose FIV status is unknown. Any new cat should be FIV tested prior to being introduced into a household with FIV negative cats. Cats that go outside should be neutered, since intact male cats are prone to fighting and therefore more likely to contact FIV. There is a new FIV vaccine available and if your cat goes outside, you should consult your veterinarian about it. The vaccine is not 100 percent effective and the major drawback to it is that once a cat is vaccinated, the cat will test FIV positive for the rest of his life. Unfortunately, the FIV tests that are currently available cannot distinguish between FIV vaccination and natural infection.

Right now, there is no cure for FIV, but infections maybe treated as they arise. Nevertheless, the best defense is preventing infection using the tactics described above.

The writers are Dr. Steven B. Holzman, Dr. William R. Haagenson, Dr. Angela N. Martin and Dr. Loretta Dougherty. They are associated with the Nassau-Suffolk Veterinary Hospital of Farmingdale.