FIV (Feline Immunodificiency Virus) In Cats

FIV (Feline immunodeficiency virus) is a viral infection that can affect cats. It is one of the most common, and therefore most infectious, diseases amongst cats.

FIV attacks a cat’s immune system. A cat with FIV will therefore have a weaker immune system compared to non-FIV positive cats, making them more prone to picking up other illnesses and infections too. This is why it is essential to keep any FIV positive cats indoors.

It can be hard to spot Feline Immunodeficiency Virus in a cat. Owners don’t commonly pick up on the initial short-lived illness, passing it off as their cat having an off-day. A cat’s immune system will then progressively decline, but many cats will still live without symptoms of the disease for years.

In fact, cats who are FIV positive can face a similar life expectancy to cats without. So while they can be more prone to picking up disease, the FIV won’t necessarily cut their life short.

How do cats catch Feline Immunodeficiency Disease?

FIV is spread through direct contact with a cat who is FIV positive, by biting and body fluids. It does not spread in the environment or air, or by sharing water and food. Deep bites from fighting, as opposed to nips from playing, are also thought to be the main concern, although there is still risk with any bite.

The disease is most commonly found in unneutered male cats. Unneutered males can fight with other males over mates, territory and food. Mating is not thought to be a way the disease is spread, although some mating practices can get violent hence why females can also have the disease.

Many people may first hear about FIV when looking at cat adoption. Cats who have been rescued as strays may be diagnosed as FIV positive, as again they may have fought with other cats over territory and food.

This is why neutering male cats is highly recommended by animal charities and rescues. It reduces a male cats urge to mate, roam and fight. While it won’t protect them from catching FIV, it will certainly reduce their chances.

On very rare occasions, a mother with FIV may pass it on to her kittens, particularly if she caught it during the pregnancy.

How contagious is FIV?

Because FIV is thought to only be spread through biting, it isn’t as contagious as a disease that would be spread through other contact or by mating.

It is referred to as Feline HIV (Human Immunodeficiency Virus). But this is because of the similarities in how it attacks the immune system and not because it is similar in terms of how it is spread.

Given the number of cats in the UK, FIV is thought to be rare in general. Yet, it can be common amongst unneutered male strays. It is still something all owners should be aware of, however.

Can humans get FIV from cats?

Non-feline animals can’t catch FIV, so if your cat were to scratch or bite you there is no need to worry.

It is also not possible for other pets, such as dogs, to catch FIV. However, if you do have or adopt an FIV positive cat, they should be kept as the only cat in the household.

Ginger and white cat with a black and white dog outside
Cats with FIV can live with dogs as it can’t be passed on to non-felines

Do I need to keep a cat with FIV indoors?

Yes. This will limit the likelihood of them fighting with another cat and spreading the disease. Even neutered cats can still fight.

You may think taking them on a walk with a harness means they won’t come into contact with another cat, which is true. However, it isn’t spreading FIV which is the concern here as such. A cat with FIV will have a weaker immune system. So, coming into contact with something on a walk could mean they pick up anything from a cold to an infection.

Something like a catio could be perfect for indoor cats who need exercise.

Charities will usually assess whether a cat with FIV can be a happy indoor cat before rehoming.

What is the life expectancy of a cat with FIV?

There is nothing to suggest a cat with FIV will have its life cut short because of the disease. It is other illnesses and infections they pick up which pose a danger, as their immune system may not fight it off.

There is a vaccine to prevent FIV, however, it is only available in the US. The efficiency of the vaccine is widely disreputed, as is the fact that it can be harder for tests to pick up FIV. It is not approved for use in the UK.

Currently, there is no cure or medication for FIV. Some vets may try immune-enhancing drugs but this can be expensive for the owner over the cat’s lifetime. Many insurance policies would not cover this, as it is seen as an existing condition. If your cat does have FIV you need to let the insurance company know.

Other factors to consider with FIV

Above are the main questions people face when having a cat with FIV, or considering adopting an FIV positive cat. However, there are also some other care issues involved.


Cats with FIV should be kept on good quality, balanced diet. Avoid raw foods or dairy – foodborne bacterial and parasitic diseases are a risk, especially for immunosuppressed individuals.

Vaccinations & vet care

All cats should have an annual checkup, but if your cat has FIV you may want to take them to the vets slightly more regularly. See what your vet says, as it depends on their overall health and age.

You also need to ensure all of their vaccinations are up to date. Any concerns you have must be seen by a vet ASAP. Anti-parasitic treatment for worms and fleas is also vital to keep up to date with.

Adopting a cat with FIV can be a very rewarding experience. Not only are you giving a cat a lovely home and life, but many who are concerned about FIV or don’t understand the disease can be put off adopting a cat with FIV.

As long as they can be kept indoors, and you don’t have any other cats, there is no reason why a cat with FIV can’t be a suitable addition to your home and provide you with many years of companionship.