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Feline Immunodeficiency Virus

What is Feline Immunodeficiency Virus(FIV)?

Feline immunodeficiency virus (FIV) is contagious among cats, and a cat can be infected with FIV for many years without showing any clinical signs of illness. Although FIV is not contagious to humans, FIV has some similarities to the human immunodeficiency virus (HIV) and has been used to help researchers better understand HIV.

How Do Cats Become Infected With FIV?

FIV is transmitted through contact with saliva from an infected cat. However, most cats contract FIV through bite wounds sustained during fights with FIV-infected cats rather than through social behaviors. Because of the territorial behavior and related aggression of cats (particularly male cats), roaming outside tends to increase the risk for exposure to FIV.

What Are the Signs of FIV?

FIV-positive cats don’t always show clinical signs of illness. Some FIV-positive cats can live a relatively normal lifespan after becoming infected. Similar to HIV in humans, FIV causes illness by attacking the patient’s immune system. Therefore, clinical signs of disease in FIV -infected cats tend to be related to illnesses other than FIV.

Clinical signs associated with FIV infection can include fever, lethargy (tiredness), chronic respiratory infections, and chronic dental, oral, and gum infections. Additional clinical signs associated with FIV infection can include chronic diarrhea, weight loss, and chronic eye and skin infections.

When cats infected with FIV continue to spend time outside, they are at increased risk for exposure to other viruses, parasites, and infections that their bodies may be unable to handle. Additionally, they are likely to sustain wounds (through cat fights or other trauma) that may become infected or fail to heal properly due to the compromised immune function associated with FIV infection. We recommend keeping FIV-positive cats indoors, which not only helps protect cats from injuries and other infections but also reduces the likelihood that these cats will transmit FIV to other cats.

How Are These Diseases Diagnosed?

We use a rapid-result test called a SNAP test to help diagnose FIV infection in cats. The SNAP test is very accurate, can be performed in the office using a very small amount of blood, and takes only a few minutes to complete.

How Are These Diseases Treated?

No medication can eliminate FIV. Most treatments involve managing the clinical signs and associated complications.

Many cats can live reasonably normal lives with FIV, so if your cat tests positive, do not despair! This result does not necessarily mean that your cat will soon become sick and die. However, infected cats may need frequent, long-term medications to control their illness. Infected cats should be monitored closely at home and should receive regular veterinary examinations to help detect signs of illness. Precautions should also be taken to protect FIV-positive cats from wounds, parasites, and other infections that can make them sick and shorten their lifespans.

When Should Cats Be Tested FIV?

Because FIV infection can have many clinical presentations, testing your cat if he or she seems to be ill is recommended—especially if a fever is present.

Kittens or cats being introduced into the home should be tested for FIV, especially if they are ill. Kittens whose mothers were infected with FIV may test positive when they are very young but test negative later as the antibodies they received while nursing from their mother wear off.

How Can I Vaccinate Against and Prevent This Diseases?

While an FIV vaccine does exist, it has been found to be unreliable and we do not recommend or carry the vaccine.

Cats that go outside are at greater risk for exposure to FIV compared with cats that stay indoors.

Protecting your cat from exposure to FIV involves minimizing exposure to other cats and knowing the FIV statuses of all the cats in your home. Any new kitten or cat being introduced into the home should be examined by a veterinarian as soon as possible and separated from all other household pets for a quarantine period of at least a few weeks. During this time, the new cat should be tested for FIV and monitored closely for signs of illness. Any problems should be reported to your veterinarian before introducing the new cat to your other pets.