What You Should Know About the FIV Vaccine — and Why Most Cats Don’t Need It

Bringing home a new rescue kitten can be an exciting time, especially if you have a resident feline that gets along well with other cats — until you discover that your new kitten is FIV-positive. Understandably, a lot of questions pop up. Could your older cat get sick? Should the cats be separated? Is there a vaccine for FIV?

At PetMed of Key West Veterinary Clinic in Dubuque, we believe in matching our vaccination recommendations to a pet’s actual risk. And in the case of the FIV (Feline Immunodeficiency Virus) vaccine, we’re careful and conservative — because while a vaccine does exist, routine use isn’t always necessary.

Here’s what you need to know.

What Is FIV?

FIV — often referred to as “feline AIDS” — is a slow-acting viral infection that affects a cat’s immune system. It’s spread almost exclusively through bite wounds, which makes it most common in unneutered outdoor males who fight with other cats over territory. FIV-positive cats can live long, healthy lives with good care — but they are more vulnerable to secondary infections, dental disease, and other complications over time.

Does a Vaccine Exist?

Yes — a vaccine for FIV was developed and is still available. However, it has limited effectiveness, especially against the many strains of the virus that circulate in the real world. And more importantly, the FIV vaccine can cause confusion in the future.

Vaccinated cats will test positive for FIV on common screening tests — making it hard to tell if they’re truly infected. This can cause major issues for cats who move homes, end up in a shelter, or need a definitive diagnosis down the road.

That’s why we do not recommend the FIV vaccine for most cats.

When Do We Recommend It?

At PetMed of Key West, we may consider using the FIV vaccine in very specific cases — such as when a known FIV-negative cat is being permanently housed with a known FIV-positive cat. Even then, we discuss the pros and cons carefully with the owner, weighing the limited protection against the long-term implications of false-positive test results.

The Best Protection Is Prevention

Since FIV is spread through deep bite wounds, the best way to protect your cat is by keeping them indoors and avoiding situations where fights with unfamiliar cats could occur. Neutering male cats, avoiding free-roaming behavior, and slow, safe introductions to other cats are far more effective strategies than relying on a weakly protective vaccine.

What About Cats Who Test Positive?

If your cat has tested positive for FIV, don’t panic. Many FIV-positive cats live full, happy lives with no signs of illness — especially when kept indoors and given regular preventative care. We’re always here to help guide care, answer questions, and support both you and your cat every step of the way.

Not Sure What’s Right for Your Cat?

If you’ve recently adopted a new cat, or are considering bringing home a second feline friend, call us at PetMed of Key West Veterinary Clinic in Dubuque. We’ll talk you through the risks, help you test if needed, and determine whether the FIV vaccine has a place in your cat’s care plan — or if there’s a better way to keep everyone safe.