Feline Immunodeficiency Virus - Frequently Asked Questions


My cat has been diagnosed with FIV, has he got feline AIDS?

A positive FIV test simply means the cat has been infected with feline immunodeficiency virus (FIV).  Being infected with FIV is not the same as having feline AIDS (acquired immune deficiency syndrome). Feline AIDS (FAIDS) describes the terminal stages of disease associated with FIV infection that may not occur for many years, and does not invariably develop in all infected cats.

Can I catch FIV from a cat?

No. FIV is a species-specific virus. This means it only infects cats. The human immunodeficiency virus (HIV) belongs to the same group of viruses, but there is no risk of cross infection.

How did my cat get this infection?

FIV is transmitted primarily by biting. Cats that are known fighters, particularly those with a history of cat bite abscesses, have a higher risk of being infected. Kittens can also be infected through the queen, if she is infected, as virus may be transmitted via the milk. Normal social interactions, such as grooming, have a low risk of transmitting FIV.

How likely are my other cats to be infected?

Other cats in the household may already be infected with FIV but show no signs of illness, so all cats should be tested. Generally, however, the spread of FIV between cats through social contact alone is very poor, so there is a good chance that the majority of other household cats may be uninfected.  

Are my other cats at risk of becoming infected?

The risk to the other cats in the household is low unless FIV-infected cats fight with others. The virus does not survive long in the environment so this is not a source of infection to other cats. However, saliva contains large amounts of virus so where possible infected and uninfected cats should be separated.

What is the long-term outlook for an FIV-infected cat?

It is often difficult to predict the long-term outlook for cats found to be infected with FIV. Typically, following infection a cat may remain in the asymptomatic phase of infection (during which there are no signs of illness) for many years. Some cats never progress to develop overt disease, whereas as others (typically after 2-5 years or more) may develop progressive immunosuppression and eventually progress to the FAIDS stage of the disease. Advances in veterinary care have helped us to support cats in the FAIDS stage for much longer than was possible in the past.

What can I do to keep my FIV-infected cat healthy?

You can help your cat by ensuring it has a healthy life-style and good quality food together with regular worming, preventive flea treatment and regular veterinary check-ups. Any infections should be treated promptly. The healthier a cat is, the longer the asymptomatic period tends to be. Keeping your cat indoors is helpful as it reduces the likelihood of your cat picking up infections from other cats as well as reducing the spread of the virus from your cat to other cats. You should avoid feeding raw meat to your cat and prevent it from hunting, where possible, as this carries a risk of Toxoplasma gondii and other infections, which can be particularly serious in FIV-infected cats.

How is FIV diagnosed?

A blood test is used to diagnose FIV infection. The test checks for antibodies against the virus that are produced by the cat in response to infection and present in the blood stream. If the test is positive it is highly likely that your cat has been infected with FIV. False positive and false negative results occasionally occur, and if there is any doubt your vet may suggest additional confirmatory tests at a specialist laboratory.

Will my cat recover?

Unfortunately not - once a cat is infected with FIV it will remain infected for the rest of its life. However, in some cats they are able to live with the virus for many years or longer without any obvious adverse effects.

What type of disease does FIV cause?

FIV causes disease by compromising the cat's immune system, so it becomes unable to fight off infections and disease in the normal way. Infected cats are also more vulnerable to developing cancer. Common signs of FIV infection include:

  • Gingivitis/stomatitis (inflammation of the gums/mouth)
  • Weight loss
  • Poor appetite
  • Fever
  • Swollen lymph glands
  • Vomiting and diarrhoea

These signs are non-specific, and also be seen with many other diseases.

Is there any treatment for FIV infection?

Secondary infections can often be treated effectively, and prompt diagnosis and management of these is important. Treatment of the underlying FIV infection is problematic. Some drugs used to help control HIV infection in humans may also be used in cats, but they cannot cure disease and are only likely to be helpful in some limited situations. Interferon (a group of naturally-produced antiviral compounds) have also been used in cats, but again with limited success. 

Should I have my FIV-infected cat euthanased?

Generally euthanasia is not necessary until the end stages of disease, where it may have to be down on welfare grounds. Like HIV infection in humans, cats with FIV have a long period where they appear healthy and show no clinical signs (the so-called asymptomatic phase of infection). This period can last for several years during which your cat can have a normal, happy life.

How can you stop cats becoming infected with FIV?

As most cats become infected from bite wounds during fighting, the risk of infection can be minimised by making sure your cat is neutered and, where possible, kept in at night (as this is the most common time for cat fights). In some countries a vaccine is also available that may be helpful where a cat's lifestyle puts it at significant risk of exposure to the virus.

One cat in my household is FIV positive and the others are not, what should I do?

There are two options: 
1. Ideally, the FIV-infected cat should be separated from other cats and not have any direct contact with other cats. Sometimes this is easiest to achieve by rehoming the FIV positive cat to a house with no other cats.
2. As the risk of infection spreading to other cats by social contact is low, many people choose to keep the FIV-positive cat. In this case, the FIV-positive cat should have a separate feeding bowl from the other cats and food should not be left down for all cats to share.

Does my FIV-infected cat still need its booster vaccinations?

It is recommended that FIV-infected cats still receive booster vaccinations, but that these should not be given any more frequently than is necessary. It is often recommended that inactivated rather modified live vaccines are given to FIV-infected cats to avoid any small risk that a modified live vaccine could cause problems if the cat was severely immunosuppressed.