Get

In Your Inbox

Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

7 FIV in Cats Vet-Approved Facts You Might Not Know About

Share

woman holding her cat in vet clinic

Feline immunodeficiency virus (FIV) is a common and serious infection in cats worldwide. This lentivirus, which weakens the cat’s immune system, is similar to the human immunodeficiency virus (HIV) responsible for AIDS in humans 1. Although cats with FIV may seem fine for a while, the virus eventually attacks their immune system, making them more vulnerable to infections that they would normally fight off. That said, most cats with FIV often enjoy a normal life expectancy, though they may need more intensive care for certain illnesses 2.

Here are various facts about FIV that can help you better understand this virus that affects feline companions all around the world.

divider cats oct 2024

The 7 FIV in Cats Facts

1.  FIV Is Mainly Transmitted Through Cat Bites

FIV primarily spreads through bite wounds from an infected cat. In rare cases, a mother cat with FIV can pass the infection to her kittens, with an increased risk if she acquires FIV during pregnancy. FIV-infected cats are also more prone to other diseases affecting the gums, mouth, digestive tract, urinary tract, and skin. They face an increased risk of certain blood cancers.


2. Unneutered Male Cats Are at Higher Risk of Contracting FIV

FIV is more common in unneutered male cats. Interestingly, only 3–5% of cats tested in North America carry FIV , unlike in Latin America, where up to 25% of cats tested are infected. The higher prevalence in Latin America may be because there are more unneutered stray cats in these regions.

male cat walking down the sidewalk
Image By: Shawn Rain, Unsplash

3. The FIV Vaccine Was Discontinued in 2016

From 2002 to 2017, a vaccine against FIV was available in North America. It was generally considered safe, with rare side effects. However, this vaccine was discontinued in 2016 for various reasons.

For one thing, vaccinated cats were at full risk of infection if exposed to strains not in the vaccine, which was particularly problematic in areas like the United Kingdom, where the vaccine provided minimal protection. Also, vaccinated cats could test positive for FIV years after vaccination due to tests being unable to distinguish vaccine antibodies from natural infection. As a result, vaccinated cats could potentially receive incorrect FIV diagnoses without further testing.


4. There Are Three Phases of FIV Infection in Cats

cat being observed by a female veterinarian
Image Credit: David Herraez Calzada, Shutterstock

FIV infection generally occurs in three phases: acute, asymptomatic, and progressive.

  • Acute phase (1 to 3 months): After infection, the virus reproduces in T lymphocytes in the lymph nodes. This phase, often benign, causes certain clinical signs in cats, such as fever, lethargy, and loss of appetite, but owners may unintentionally ignore them or attribute them to other causes.
  • Asymptomatic phase (months to years): After the acute phase, the virus replicates slowly, without cats showing any apparent signs of illness. However, they may have abnormalities in blood tests. Some remain at this stage without progressing.
  • Progressive phase (variable): The virus spreads and weakens cats’ immune systems, making them vulnerable to secondary infections. They can develop skin, eye, urinary, or respiratory infections and severe dental issues and have a higher risk of cancer. If several critical issues occur, the survival time is typically only a few months.

5. Cats Infected With FIV Can Have Normal Lives

Although there is no known cure for FIV, cats infected with it can still live a good life if they receive proper management. However, if an FIV-infected cat experiences severe illnesses or persistent fever and weight loss, their prognosis is generally less favorable.


6. There’s One Simple Way to Protect Your Cat From FIV

In the absence of an FIV vaccine, the best way to protect cats is to avoid exposing them to the virus. Since cat bites are the primary means of spread, keeping cats indoors reduces the risk. Introducing only infection-free cats to homes with uninfected cats can also prevent infections.

vet holding a cat
Image By: Yana Vasileva, Shutterstock

7. FIV Can’t Be Transmitted to Humans

Despite its similarity to HIV, FIV is strictly a species-specific virus, affecting only felines. There is no evidence supporting FIV transmission or disease in humans. While it’s termed “feline AIDS” due to its resemblance to HIV, FIV exclusively infects cats and poses no threat to people.

divider 2 cats

Conclusion

Although FIV is an incurable disease, it does not necessarily carry a death sentence. Many cats can enjoy long, beautiful lives despite having an FIV diagnosis. The important thing here is to provide them with appropriate veterinary care, depending on the stage of the virus and how their immune system is affected. Numerous clinical trials are also looking at new antiviral drugs to prolong the lives of cats affected by FIV.


Featured Image Credit: Vladeep, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything cat

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.




How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Catster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.


Catster's Digital Magazine is Back!

Vet-approved health & behavior advice

Real cat stories & community features

Chatting About the Importance of Spaying/Neutering, Cat Retail Shopping Ban & Red-Level Storms | Chatty Cattys, Episode 30

In this episode of Catster’s Chatty Cattys podcast, Nicole and Dr. Karyn are celebrating a major legal win for pets before diving into...

Is Your Cat Happy? Here’s How You Can Tell

Cats have a reputation for being indifferent, even inscrutable. But despite their seemingly ambivalent appearance, cats experience many emotions, including happiness, and they...

Human Brains Age Like Cats – New Study Debunks the 7-Year Rule

If you’ve ever caught your senior cat staring blankly at a wall, wandering the halls at 3 am, calling out for no clear...

Chatting with Devin About Here! Have a Kitten, Fostering, & Why Two Are Better Than One | Chatty Cattys, Episode 29

In this episode of Catster’s Chatty Cattys podcast, Nicole & Dr. Karyn sit down with Devin, the founder and one-woman show behind “Here...

More related

Ask Dr. Paola – Help! My Cat Pees on My Bed (April 27, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

Why Do Cats Meow & Yowl? 10 Vet-Approved Reasons Behind the Behavior

Your cat’s meow can have many different motives, and there is usually no reason for concern. Cats will meow when they’re hungry, full,...

How to Give a Cat Liquid Medicine: 8 Vet-Approved Tips

Your furry friend being sick makes you feel horrible, especially when there isn’t much you can do to make them feel better. It’s...

Longest Cat Whiskers in the World: 2026 Record Holders

The record holder for the longest whisker on a cat belongs to Missi, a Maine Coon in Finland with an incredible 7.5-inch whisker....

Keep reading

How to Tell if My Cat Has Worms? 5 Vet-Reviewed Signs

Parasitic worms are repulsive to think about, but they’re a common health problem for cats. Along with being off-putting, worms can cause severe complications for your cat if left untreated. Fortunately, worms can be treated safely and effectively in cats,...

cat owner belly rubbing her cat

5 Best Litter for Cats with Asthma in 2026 – Reviews & Top Picks

It can be tough to parent a cat with asthma, particularly because of cat litter. The tiny particles and dust that get kicked up when a cat litter box is being cleaned can really affect asthma-suffering cats. Many people therefore...

kitten in the litter box

Is It Safe To Dye Your Cat’s Fur? Vet Approved Advice

If you’ve been online and pictures of cats with dyed coats have crossed your path, you may be wondering how the process works, what it involves, and whether it may be something to consider doing with your companion. In theory...

woman preparing dye for hair coloring on pink background

Do Cats Play Fetch? Trainable Breeds & Useful Tips

Fetch has long been associated with dogs. This active game is so pleasing to dogs, as they’ve spent centuries domesticated to work with and for humans, many for retrieving purposes. Cats have also been domesticated for a long time, not...

Main Coon running on a field

Is Dracaena Toxic to Cats? Vet-Reviewed Houseplants Examined

Having live houseplants adds a nice touch to your home and helps to keep your air clean, but our feline companions do enjoy playing with leaves and flowers. While many plants are safe, some common houseplants, like dracaena, are toxic...

Catster_Is Dracaena Toxic to Cats

Why Does My Cat Pee In The Litter Box But Poop On The Floor? 9 Vet-Reviewed Reasons & Solutions

For some, dealing with the litter box is easy. But for other cat owners, not so much. Here’s the thing—cats are finicky creatures, especially when it comes to the litter box. A tiny detail can cause a cat to start...

man holding a plastic shovel is removing cat poop from the litter

How to Care for a Disabled Cat With Special Needs: 11 Tips to Prepare Your Home

Disclaimer: This article has been reviewed by a qualified veterinarian using information available at the time of review. The knowledge of feline medicine is continually evolving. This article is not intended to replace consultation with a veterinarian for your specific...

tabby longhair cat standing outdoors in the garden with walking aid or wheelchair

7 Things My Cat Does While I’m Taking a Shower

Cats are notorious for watching people while they’re trying to shower, and most cats do strange things in bathrooms from time to time. Some like to stare at their owners in the shower, and others like to play with the...

Bengal cat standing on the bathtub

Love Cats? So Do We! Join the Catster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Catster Email Newsletter

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.