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.

Can FIV+ Cats Live With Other Cats? Our Vet Explains the Science

Female vet holding a sick cat close-up

Feline immunodeficiency virus (FIV) is a cause of an infectious disease of cats. It is similar to HIV (human immunodeficiency virus) in people, which is the cause of AIDS. Feline immunodeficiency virus attacks the immune system and weakens it. FIV is a complex disease, and there is unfortunately no cure.

A big worry for owners of cats that are FIV-positive is whether they can safely live with other FIV-negative cats in a multicat household. Recent research has led vets to believe that the disease is not as easily transmissible as previously thought. However, it is not generally recommended to keep FIV-positive cats alongside FIV-negative ones as the risk of transmission still exists in case of fighting.

This article will discuss the facts surrounding FIV transmission and explore the risks of co-housing FIV-positive cats with FIV-negative ones.

divider 1 paws

What Is Feline Immunodeficiency Virus?

FIV is a slowly progressive virus that works by damaging cells in the cat’s immune system. The ongoing destruction of cells that are integral to the body’s defense mechanisms leads to a weakened immune system. When the immune system response is compromised, cats will become vulnerable to secondary infections. One of the challenging parts about the diagnosis of cats with FIV is that they can be positive but have no clinical signs during the asymptomatic or latent stage of illness. Cats can harbor the infection for years and clinical signs may not be apparent for a long time.

FIV weakens the immune system of cats to the extent that they can become very unwell from illnesses that a healthy cat would be able to survive. There is no cure for the virus, only management strategies.

Clinical signs can be very subtle or generalized and non-specific. Typical signs to look for include:

  • Weight loss
  • Lethargy
  • Fever
  • Reduced appetite
  • Secondary lesions in mouth and on gums
  • Poor coat condition
  • Swollen lymph nodes
  • Discharge from eyes and nose due to secondary respiratory infections

The cat may also be generally run down and take longer than usual to recover from infections. If you see any of the above clinical signs, it is important to make an appointment with your vet so that they can be examined.

loss weight or skinny cat
Image Credit: Aun25, Shutterstock

How Is Feline Immunodeficiency Virus Transmitted in Cats?

Cats that are infected with FIV typically shed the virus in their saliva. The infection is passed on when an infected cat that is actively shedding the virus bites another cat. This contaminates an open bite wound with the virus. Cats can also become infected by transmission of other bodily fluids, such as blood, and less commonly, FIV can also be transmitted sexually.

Kittens can become infected in utero, less often during birth, or just after birth. It is believed that the virus can pass across the placenta and through the mother’s milk to the kittens. Interestingly, transmission of the virus from the queen to the kittens only occurs in only a small percentage of cases.

The good news is that FIV is not capable of surviving for long periods outside of live cells. This means that it is less common for cats to pick it up in their environment. A lot of cats that are FIV positive are known to be fighters in their neighborhood, which is how they contracted the virus. Cats that present with cat bite abscesses should be tested for FIV 8 weeks after they have been bitten to screen for the disease.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's an online service where you can talk to a vet online and get the advice you need for your pet — all at an affordable price!

PangoVet_Mention-in-Content for PangoVet2 save money

How Is Feline Immunodeficiency Virus Diagnosed in Cats?

FIV can be complicated to detect. It is diagnosed using a blood test that identifies the presence of specific antibodies to the virus. A test called an ELISA is commonly used. If the test comes back positive, this means that the cat has been exposed to the virus and has produced antibodies. It can also mean that the cat is currently infected by the virus, but the test may produce false positives. These can occur if a cat has received a vaccination against FIV. The test is not able to tell the difference between antibodies produced by an infection with the disease and antibodies induced by a vaccine.

If a cat has been recently infected, they may produce a false negative test as antibodies to the virus can take anywhere from 8 weeks to 6 months to develop. False positive tests may also be seen in young kittens who have received antibodies from their mother across the placenta or via the milk when nursing. Because of this, any kittens that are 4 months old or younger and have tested positive, need to be retested when they are over 6 months old.

Due to these issues with testing, it is recommended that any cats testing positive should be retested at a later date. The blood test should be sent off for a PCR test or a Western blot test as these are more definitive and can give more comprehensive results.

Hand holding blood work samples in test tubes
Image Credit: Belova59, Pixabay

What Does the Research Say?

Recent studies have suggested that there is a low risk of transmission through casual contact in multicat households. There have also been suggestions that the presence of Feline Leukemia Virus (FeLV) could increase the risk of FIV transmission.1 This is why it is so important to test cats for viruses such as FeLV before introducing them to FIV-positive cats.

Cats that are kept indoors and therefore do not encounter other cats not in their household have a lower risk of potential transmission.

Vaccines and FIV

There are some vaccines available for FIV, but it is not clear how reliable they are. A vaccine has not been available in the United States since 2016, and is currently available mainly in Australia, New Zealand, and Japan. Vaccines are also problematic when it comes to interpreting the results, in that a cat that has been vaccinated will test positive for FIV. There is no way to determine if the antibodies have been made in response to an infection or if they have been induced by a vaccine.

There is no known benefit to giving the vaccine to a cat that is already infected with FIV. Therefore, it is necessary to test cats and kittens whose clinical history is unknown before they receive a vaccination.

cat-having-a-vaccine
image Credit: Africa Studio, Shutterstock

Can FIV-Positive Cats Live with FIV-Negative Cats?

If a cat is FIV-positive, ideally, they should not be housed with FIV-negative cats. There are some conditions where FIV-positive cats can live with FIV-negative cats, but owners need to be aware that this is not generally recommended, as the risk of disease transmission is still present, however small.

Factors that influence the likelihood of transmission include:
  • Group Dynamics: If the cats are familiar with each other and get along well, the risk of them fighting and biting each other is much lower. This means the main route of transmission is removed if you know the cats won’t fight. While this may be reassuring for owners, cats are animals that act on instinct and there is no guarantee they will not fight.
  • Age: Young kittens and very elderly cats are more susceptible to FIV transmission than adult cats.
  • Veterinary Attention: It is important that all cats are taken to the vet regularly for checkups and are given all the correct vaccinations and parasite treatment. This is to ensure they are in good health and to minimize the risk of secondary infections.
  • Nutrition: It is important to feed all cats a well-balanced diet that includes all the essential vitamins and minerals to ensure they are as healthy as possible.
  • Neutering: Neutering cats reduces the risk of the virus being transferred during mating, although this is not a very common route of transmission. FIV can be transmitted through the transfer of bodily fluids during sexual intercourse. Cats that have been neutered are also less likely to roam as far and are less likely to be aggressive towards other cats and fight, as most commonly, the virus is transferred by bites.
  • Other diseases: It has been suggested that the presence of Feline Leukemia Virus (FeLV) could increase the risk of FIV transmission. All cats should be tested for FeLV before being introduced to a FIV-positive cat in any circumstances.

veterinarian holding the cat
Image Credit: H_Ko, Shutterstock

How to Care for a Cat with FIV

Cats with FIV can still live a long and healthy life despite having the disease. There are a few changes that need to be made, which include:

  • Housing them on their own if possible: As mentioned above, cats with FIV should be housed in a single-cat household. To prevent the spread of FIV, it is vital that FIV-positive cats are kept on their own, no matter how small the risk may be.
  • Keeping them indoors: If you have a cat that has tested positive for FIV, it is important to keep them indoors. This prevents them from picking up other illnesses, as well as protects other cats they come in contact with, in case of a cat fight. Owners can allow their cats access to the outside world by using a “catio” setup or letting them out in their own backyard supervised on a leash.
  • Ensuring they are in good health: It is very important that FIV-positive cats are kept as healthy as possible. They should be taken to the vet as soon as they show any clinical signs of being ill. They should be vaccinated and up to date with flea and worm treatment.

divider 2 cats

Conclusion

It is generally not recommended to house FIV-positive cats alongside cats that do not have the infection, unless it’s a well-established social group where there is no fighting. There are many ways to reduce and minimize the spread of the disease, and the risk of transmission is lower than previously believed. Despite all this, it does not matter how many precautions are taken, there is still a chance the disease will be passed on to other cats.

FIV can be a debilitating disease and vets and owners must commit to minimizing the spread of the virus to reduce the number of cats affected.


Featured Image Credit: megaflopp Shutterstock

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

2 Responses

  1. Hi.
    My neighbor's kids have 2 FIV+ cats in their house. The cats have no visible symptoms and present no indication of being anything but very friendly, slightly overweight house cats. The kids came over to my house yesterday to see my 2 indoor-only FIV- cats. They had a great time feeding my cats treats, petting them, and throwing toys for them.

    They said their vet said they would not infect anyone else's cat by simply visiting their home and petting their cat, leaving their 2 FIV+ cats home, having no direct contact between the FIV+ cats and FIV- cats.

    Is that true? Do I have anything to worry about?

    1. Hi Esther, thanks for reading us, don’t worry, the form of transmission of FIV between cats is through puncture wounds like scratches or bites. The kid can not play a role in transmitting the disease to your cats, that said please avoid introducing the cats to your cats. Kind regards and we hope this helps.

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.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

8 Vet-Verified Ways to Be an Eco-Friendly Cat Owner in 2024

Owning a pet takes a lot out on the environment. After all, our pets have needs too, and these needs require resources that...

How Do You Keep a Cat From Getting Bored? 12 Vet-Approved Tips

Cats are remarkable pets that make excellent companions for children and adults. They are playful, friendly, and fairly easy to maintain. They are...

Purple Leash Project: What It Is & Why It Is So Important

We likely all know a victim of domestic violence and are familiar with the devastation that comes with it. Survivors know all too...

15 Shorthaired Cat Breeds (With Info & Pictures)

Cats come in all shapes and sizes. While they don’t have the same diversity as dog breeds, cats have different physical traits. Shorthaired...

More related

National Feral Cat Day 2025: How & When Is It Celebrated?

National Feral Cat Day is celebrated on October 16th. It’s been around since 2001 when Alley Cat Allies, an organization dedicated to improving...

How to Help Control Fleas in Feral Cats: 5 Vet-Approved Tips & Tricks

Most feral cats have difficult lives; one common problem they face is being infested with fleas. The parasites can be quite dangerous and...

What Are Cats Scared Of? 8 Vet-Reviewed Feline Fears & How to Help 

Cats are highly attuned to their environment and are sticklers for routine. This sensitivity can make them easily startled by certain objects, sounds,...

Why Do Cats Eat and Chew on Paper? 4 Reasons for This Behavior

Believe it or not, cats chewing on cardboard and paper is a problem that some pet parents encounter. Sometimes, owners mistake their cats...

Keep reading

Do Female Cats Spray? Vet Approved Facts & FAQ

It’s a common misconception that only intact male cats spray. The truth is spraying is not a sex-specific feline behavior. Female cats can and do spray. Having a female cat that sprays at home can be frustrating, especially if you...

a white cat spraying the wooden gate

Why Does My Cat Eat So Fast? Vet-Approved Feline Facts & FAQ

Do you ever watch your cat scarf down their food and wonder why they eat so fast? There might be a reason for their speedy eating habits—cats are hardwired to eat quickly to protect their food from predators. In the...

maine coon cat eating

Do Cats Feel Remorse or Guilt the Same Way Humans Do? Dealing With Bad Behavior (Vet-Reviewed)

While your beloved cat feels connected to you, he won’t feel bad if he pees or poops outside the litter box, scratches up your furniture or does something outrageous in your home that creates chaos. Unlike us humans who feel...

Sad, calico cat sitting, looking through small front door window on porch

Can Cats Eat Black & Green Olives? Vet-Verified Nutritional Science & Info

If you have ever been snacking on a jar of olives, you may notice your cat curiously sniffing whatever you’re snacking on. This may cause you to wonder whether or not cats can eat black and green olives. Since olives...

olives-pixabay

How to Take Care of Your Cat’s Teeth: 8 Vet-Verified Tips

Dental problems are pretty common in cats. When plaque sits on their teeth, it hardens and develops into tartar. Tartar around the gum line causes irritation and inflammation that results in gingivitis, which can lead to full-blown periodontal disease and...

hand showing the teeth of blue tabby maine coon cat

Why Do Cats Like to Cuddle? 5 Vet-Verified Reasons

There’s arguably nothing better than a warm cat cuddling on your lap while you relax on the sofa. While cats have a reputation for being rather aloof and independent creatures—and some are somewhat deserving of that reputation—many cats defy the...

senior woman cuddling her cat

Why Your Cat Is Hiding Under the Bed: 9 Vet-Reviewed Reasons & Tips

Cats are interesting creatures. They can be crabby, interactive, standoffish, or comical. It can be challenging to decipher why a cat does what they do, especially regarding things like hiding under the bed. So, why would your cat hide under...

cat hiding under the bed

Can Cats Eat Ramen Noodles? Vet-Reviewed Facts & FAQ

After leaving your ramen noodles on the table, when you answer the door, you may have noticed that your cat had sampled your meal. Should you rush them to the ER? Are ramen noodles safe for cats to eat? A...

Can Cats Eat Ramen Noodles