F.I.V. (Feline Immunodeficiency Virus) 

Honeycat Rescue takes pride in taking in and rehoming cats with FIV but often this is a confusing and concerning topic for potential adopters and we’d like to clarify exactly what it means and why cats with FIV are perfectly wonderful additions to your family.

What is FIV?

FIV is Feline Immunodeficiency Virus and is not the same thing as FeLV (Feline Leukaemia) - they are two different viruses. They may be spoken about at the same time as they are often tested for in a combination tests at vets but they affect the cat in very different ways. Cats with FIV can live long and happy lives whereas FeLV is a serious risk to a cat's health and longevity.

Feline Immunodeficiency Virus (FIV) has been linked with cats for years, although it was only given a label in around 1986. The nature of the virus is that it reduces the number of white blood cells, which eventually makes the cat less able to fight off infection. However, because it is such a slow acting virus many FIV positive cats can have a normal lifespan with no obvious health issues resulting from the virus. FIV is species specific. It can only be transmitted from cat to cat, not to humans or other animals.


FIV belongs to the same group as Human Immunodeficiency Virus (HIV) and for this reason has received much greater attention than it would otherwise have done BUT IT DOESN’T WARRANT THE SAME CONCERN. The mere mention of FIV, and the fact that it is sometimes inaccurately known as 'Feline Aids', strikes unnecessary terror into the heart of many cat-owner and it is worth taking time to LOOK AT THE FACTS. The  strains used in labs on experimental cats were very virulent, and much previously published information is based on this. However, FIV strains in cats living normal lives tend to be much less severe, and may never cause disease.

How does a cat catch FIV?

FIV is in the cat’s blood and saliva of those infected with it but it cannot survive long outside of its host and requires a high dose to infect another cat. The main way a cat passes it on is through biting another cat. Cats who are more inclined to fight are obviously more likely to be infected and therefore, toms who haven’t been spayed are most at risk – this means feral cats who haven’t been neutered often have more likelihood of FIV than non feral cats and it also illustrates how important it is to neuter to prevent the cycle continuing.

It is very unlikely for the disease to be passed in a group of cats who do not fight and it can’t be passed on by sharing food bowls or being on clothes or hands of humans. Recent reports even suggest that the likelihood of cats with FIV passing it on to cats in the same household is as low as 1-2%.

Stopping your cat from getting FIV

There’s only one sure way of doing this and that’s by never letting your cat go outside and therefore there being no chance of it coming into contact with other cats. This is unnecessary though as it will reduce the quality of life for the cat and the chances are incredibly low that the cat will get it. The best option is to neuter your cat which will reduce the likelihood of it fighting, wandering and also help prevent any future strays.

What are the signs of FIV?

There are many different signs of FIV and it a blood test is normally needed to tell for sure. The cats may have raised lymph nodes 6-8 weeks after being infected and they may have symptoms like a temperature, diarrhoea or conjunctivitis may develop, possibly lasting days or even weeks, with the cat then returning to apparent health. Other common signs are gingivitis (gum inflammation), sneezing, snuffling, a discharge from the nose or eyes, or kidney failure. The eyes or brain can be affected in a very small number of cases, resulting in changes in behaviour.

The fact that the virus depletes some of the white blood cells (T lymphocytes), in theory at least, makes the cat more susceptible to other infections, and it will find it more difficult to shake them off. This is known as 'immunosuppression' and is identical to the situation in HIV infection but this is purely theoretical, and in practice many cats do not have any more infections than cats which are not infected with the virus.

The most common infections for FIV positive cats to have are gingivitis and stomatitis (inflammation of the gums and other parts of the mouth). However, FIV isn’t the most common cause of gingivitis. This is common in cats which are fed on an unnatural diet of sloppy canned food. Cats which are carriers of Calici-virus (one of the cat flu viruses) frequently suffer from gingivitis, as well as lot of cats which do not carry either of these viruses. 
Whatever the cause, gingivitis is treated initially with a thorough dental scale and polish plus a course of anti-biotics and a steroid drug to suppress the inflammation. Various other chronic infections may also occur - conjunctivitis, diarrhoea, skin and respiratory tract infections (rhinitis or bronchitis). However, these are less common, and again, respond to treatment providing it is carried on for an adequate time.

What is their Life Expectancy?

A cat who contracts FIV will usually still have a strong immune system for several years after infection, it is only over time, that the effects of the virus may start to show, and even then, most infections can be treated with the appropriate medications. With love and good care however, many FIV+ cats can live normal lifespans. These days, it's not unusual to find FIV+ cats reaching 15 years or more. 


A ten-year FIV Monitoring Project was carried out at Glasgow Veterinary School involving 26 cats and the results indicated that a higher percentage of FIV negative cats died during the period of the study than FIV positive cats, and that FIV infection did not affect the cats' life expectancy. 

So Why the Unfounded Fears about FIV?s

FIV in stray cats has caused a lot of the unfounded fear linked to the virus with toms picking it up and passing it on and because these cats have nobody to look after them, once they have been captured and taken to the vets, they have already have secondary issues, which haven’t been treated and it’s often too late for them. In fact, there are very many more healthy FIV cats than ill ones.  

Adopting an FIV positive cat

FIV positive cats can often live long lives, and often will live longer than non-infected cats, especially if kept indoors away from potential adversaries. However, due to their somewhat reduced immune system, the cat may succumb to illness earlier and though treatment is often successful, some may not reach their normal life expectancy. FIV cats will need fast veterinary assistance for even small symptoms but with good care, many FIV positive cats will live normal lifespans.

One American study showed that FIV+ cats are far more likely to lose their lives through being euthanised, because no-one was willing / able to offer them a home, than from any effects of the virus.

FIV positive cats still find it harder than most to find new homes, even though in all other respects they are normal, loving cats, and deserve a chance at a happy life. If you think you might be able to give a home to an FIV cat, please talk to us as we are very keen to help cats who are FIV positive to find loving homes.




Can FIV-positives and FIV-negatives live together?

The most recent research carried out at Glasgow University's Companion Animal Diagnostics indicates that the chances of FIV being passed from one cat to another in the same household is approx 1-2% but we would recommend that they are not rehomed with FIV negative cats, just as there is still a risk, even if it is 1 in 100. That being said, even if FIV is passed on, it doesn’t mean it will be life-threatening, as previously discussed.


The Celia Hammond Animal Trust have been conducting a long-term study at their sanctuary since the late 1990's, where FIV-positive and FIV-negative cats live happily together, grooming each other and sharing food bowls and litter trays. Regular blood tests for the virus are carried out, and to date no cases of transmission have yet been found. If a cat is FIV positive but happy and neutered, it is unlikely to get into fights and pass FIV on.

Should FIV+ cats be allowed outside?

We would suggest that your FIV positive cat be indoor only or in an enclosed garden, just to prevent any tiny chance of the spread of disease and an enclosed garden or ‘catio’ can be a great compromise and enhance their quality of life.

This is another reason why neutering is important as unneutered cats are far more likely to try to get outside and want to wander, so please make sure that if your cat has been diagnosed with FIV and it is unneutered, then you need to book it in to be operated on ASAP! 

Caring for your FIV+ cat

Lots of love and TLC  can help your FIV+ cat to enjoy a long and happy life. Love is a powerful immune system enhancer - so give your FIV+ cat all the love and affection it desires! Keep their regular annual vaccinations up to date, but check with your vet about vaccinating if the cat is suffering symptoms. A good diet will help, including vitamin supplements such as buffered vitamin C (sodium ascorbate) and vitamin E, which builds immune system strength but again, check with your vet.

At any sign of illness, take your cat to the vet, as early treatment can prevent many problems. Antibiotics can control infections, and FIV+ cats who reach a chronic stage may rely on antibiotics more frequently.

Boarding your FIV cat

Boarding catteries should have no problem accepting an FIV cat, since the virus cannot be transmitted by feeding equipment etc. The cattery will need to know that they are FIV+, to ensure that they are not allowed contact with other cats, and also so that they can keep a close eye for any symptoms of illness, and act quickly.

Insuring your FIV cat

Most pet insurance companies are likely to agree to insure an FIV positive cat, however they may add extra 'exclusions' in the policy for anything they might consider to be FIV related. Ask around different insurance companies, to compare what they will cover. Even with exclusions, we still recommend taking out insurance for your FIV cat. A good back-up plan is to set up a regular direct debit into a savings account, to build up some extra funds in case something crops up that your insurance policy doesn't cover.


FIV positive cats should always be neutered, however if a female FIV positive cat is allowed to become pregnant it is extremely rare for the kittens to become infected with the virus. FIV differs from feline leukaemia in that respect, in that it is not passed on from the queen to kittens in utero. However, kittens born to an infected mother will absorb antibodies from her milk and will therefore give a positive response to the FIV antibody test. In these kittens the test becomes negative after 12-16 weeks, as their maternal immunity wanes. It is therefore pointless to test kittens under 16 weeks using an FIV antibody test.

Even though it is rare for kittens to be born FIV positive, if there is a clinical need to find out their FIV status, the University of Bristol, Langford Veterinary Diagnostics can carry out an antigen test, which detects the presence of the viral DNA itself rather than just the antibody. This is a relatively expensive test, but if needed, information can be obtained from them by Email: vet-path@bristol.ac.uk

Further information & advice

Catwork Sanctuary - Introduction to FIV: www.fivcats.com/FIV/fiv_introduction.html
Celia Hammond Animal Trust - What is FIV?: www.celiahammond.org
Chat to other FIV owners on the Cat Chat Forum » Feline Forum: the 'FIV Owners Club'
Catwork Sanctuary - Should FIVs be 'indoor-only'? » fivcats.com/FIV/fiv_indoor_only
'80 FIV Cats' - Catwork Sanctuary's booklet about FIV » fivcats.com/FIV/80_fiv_cats_booklet