FIV – Feline Immunodeficiency Virus

We are all familiar with Human Immunodeficiency Virus (HIV), the virus that causes Acquired Immunodeficiency Syndrome (AIDS) in people. HIV suppresses the immune system of affected individuals and results in a chronic illness that eventually progresses to AIDS, a fatal disease of which there is no cure. Individuals with AIDS are susceptible to infection and cancer as a result of the severe suppression and weakening of the immune system that accompanies this disease. Infected individuals often die from illnesses that would be easily conquered by the immune system of a healthy individual, such as the flu or the common cold.

A similar type of situation occurs in cats when they are infected with Feline Immunodeficiency Virus (FIV). Infection with FIV suppresses the cat’s immune system and makes it susceptible to a whole host of diseases and cancer. FIV is found all over the world and is transmitted between cats, most commonly through saliva and blood from bite wounds and scratches. Since outdoor or free roaming cats are more likely than indoor cats to get caught up in neighbourhood cat fights, they are at a higher risk for FIV infection. Sexually mature males that go outdoors or are free roaming are at the greatest risk for infection because they fight ferociously for the right to mate and hold territory. Although FIV is spread between cats, it is not transmissible to humans, even if bitten by an infected cat. An infected cat can still make a good pet as long as it is in a single cat household or is kept separate from other cats to prevent the spread of the virus.

Cats do not show immediate signs of infection but as the disease progresses they become immunosuppressed and are attacked by opportunistic infections. In most situations, cats are brought to the veterinarian for things like upper respiratory tract infection, cancer, or general indications of not feeling well, such as depression, anorexia, and weight loss. In other words, these cats are brought to the vet because they are showing signs of the secondary infections that occur because of the immunosuppression caused by FIV.

FIV can be detected quite easily with a blood test and most veterinary clinics use an ELISA Snap Test to check for the presence of antibodies to the FIV virus in the cat’s blood. Keep in mind that no test is 100% accurate and that a positive blood test should be verified with a second method of detection. Another important point to note is that as with AIDS in humans, infection may not be detected initially after exposure. Just like health care workers who have been pricked by a needle, cats that have been in a cat fight will need to be tested up to 6 months after exposure to ensure that they are clear of the virus. Kittens should not be tested until they are six months old because they may still have antibodies to FIV circulating in their blood that they received from their mother and this can cause them to test positive when they are not in fact infected.

Similar to HIV and AIDS, there is no cure for FIV infection. All that can be done is supportive care and treatment of the secondary infections. Cats with FIV may have a very good quality of life for several years but eventually they will succumb to the immunosuppression that accompanies infection. All cats that are FIV positive should be kept indoors to prevent infection of other cats in the neighbourhood.

There is a vaccine for FIV but its use is controversial. Vaccines work by stimulating the body to produce antibodies against the virus that is being vaccinated for. These antibodies circulate in the blood and allow the body to mount a strong and speedy immune reaction to the virus should the animal ever come into contact with it in the future. Since the most common method of FIV detection in cats is a test that looks for the presence of FIV antibodies in the blood, we are presently unable to tell the difference between truly FIV positive cats and those that have been vaccinated for FIV. Therefore, if you vaccinate your cat against FIV it will test positive for FIV using the standard ELISA snap test that is employed by most veterinary hospitals and shelters. The sad reality is that an FIV-vaccinated cat that becomes lost and is picked up by a shelter or animal hospital and not claimed within the specified time frame is likely to be euthanized as an FIV positive cat.

Lifestyle is the key factor that affects a cat’s risk of becoming infected with FIV. To protect your cat from FIV keep it indoors to reduce its exposure to stray or roaming cats that are at a high risk of being infected. Neuter all male cats that go outdoors to eliminate their drive to fight for mates. Any new cat that is introduced into your household should be tested for FIV by your veterinarian. Responsible pet ownership is the key to keeping this deadly virus at low levels in the environment.

By Melanie Youngs – Pets.ca writer