Blog by Dr. Cindy Carter

Good morning, class!! Today (and next time) we’re going to talk about Feline Immunodeficiency Virus (FIV) and Feline Leukemia (FeLV), two diseases that we can encounter in our feline friends, especially those that live outdoors. We’ll discuss their transmission, symptoms, and long-term effects, and by the end of this two-part blog you’ll be a pro. If you still have any burning questions afterward, be sure to ask me at your next appointment! 😉

What is FIV?

Feline immunodeficiency virus is mainly a disease of cats that spend a lot of time outdoors, and is spread by bite wounds. It can also be passed from mother to offspring, though luckily even if young kittens come up positive on their first testing they may be able to clear the infection within a few months.

Cats that are infected with FIV may show no symptoms at all for many years, but due to a suppressed immune system they are more susceptible to infections. The virus itself doesn’t cause disease, and infected cats may live for many years with no symptoms at all, but some common secondary issues we do see are: fever, weight loss, ocular (eye) disease, persistent diarrhea, oral disease, and upper respiratory infections. Additionally, FIV infected cats are more prone to development of cancers, especially lymphoma.

How do we diagnose it?

We recommend screening outdoor cats, especially males that get into fights, regularly. It is also a good idea to test pregnant females as the disease can cause abortions and stillbirths, though transmission to kittens isn’t common. Testing can be done along with yearly bloodwork during an annual exam. The test we use screens for antibodies to FIV, which are markers that show exposure, but definitive diagnosis requires a more specialized test call a Western blot which is done at an outside lab. Kittens less than 6 months old may show a positive result on our test due to passive transfer of antibodies from their mother, but often clear the infection by 8 to 12 months of age. Additionally, there was an FIV vaccine developed which has not been widely used in large part because it causes false positives on testing, making it difficult to determine who is truly infected and who has just been vaccinated.

What if my cat is positive?

• Keep kitty indoors away from other cats to prevent spread. Dogs are not susceptible to infection.
• They can still live a nice life, but may be diminished in years. Over half of diagnosed cats remain symptomatic lifelong, but about 20% only survive past 2 years after diagnosis, as they succumb to secondary diseases.
• FIV positive cats are more prone to chronic and recurrent health problems, so it is important to have them examined soon if any symptoms of opportunistic disease occur, i.e. if they develop diarrhea, sneezing, weight loss, inappetance, etc.
• FIV doesn’t progress to “AIDS” and we don’t keep most cats on any constant medications unless they have severe clinical symptoms.

There you go, FIV in a nutshell! Stay tuned because next time we’ll go over a similar subject: Feline Leukemia Virus.