My cat has been diagnosed as FIV positive. Has he got feline AIDS?

FIV positive simply means the cat has been infected with feline immunodeficiency virus (FIV).  Being infected with FIV is not the same as having feline AIDS. Feline AIDS (FAIDS) describes the terminal stages of disease associated with FIV infection that may not occur for many years.

Can I catch FIV from a cat?

No. FIV is species-specific. It only infects cats. Although human immunodeficiency virus (HIV) in man belongs to a similar group of viruses 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 diagnosed as FIV positive. Kittens can also be infected at birth, probably through virus that is present in the queen's milk. Around a quarter to a third of kittens born to an infected queen are likely to be infected themselves. Normal social interactions, such as grooming, have a very 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. 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 still be uninfected. 

Are my other cats at risk of becoming infected?

The risk to the other cats in the household is low unless the FIV-infected cat is a fighter. The virus does not survive long in the environment so this is not a source of infection to other cats. However, saliva can contain large amounts of virus so it is advisable to feed the FIV-infected cat separately.

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

It is not always possible 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 external signs of illness) for many years before declining in 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 as healthy as possible?

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 and aggressively. The healthier a cat is, the longer the asymptomatic period tends to be. Keeping your cat indoors is also a good idea 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 infection which cause particularly serious illness in FIV-infected  cats.

How is FIV diagnosed?

A blood test is used to diagnose FIV infection. The test checks for an immune response (antibodies) to the virus. If the test is positive it is likely that your cat has been infected by the virus. False positive and negative results do occur for a variety of reasons. For example, antibodies to the virus present in the bloodstream of an infected queen can pass via the milk into an uninfected kitten giving a false positive test result. Kittens under four months of age that test positive should therefore be retested when they are six months old. Commercial laboratories also offer additional diagnostic tests for FIV including the polymerase chain reaction (PCR) test.

Will my cat recover?

Once a cat is infected with virus it will remain infected for the rest of its life.

What type of disease does FIV cause?

FIV causes disease because it destroys the cat's immune system so it becomes unable to fight off infections in the normal way and is vulnerable to developing cancer. Common clinical signs of FIV infection include:

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

A lot of these signs are very non-specific and many diseases can have a similar clinical picture.

Is there any treatment?

Secondary infections can be effectively treated with antibiotics but there is no specific treatment available for the virus. Some cats have been treated with human anti-HIV drugs including AZT (azidothymidine) and interferons with limited success. Evening primrose oil (550 mg daily) seems to be helpful particularly in the earlier stages following infection.

Should I have my cat euthanased?

Generally euthanasia is not necessary until the end stages of disease. 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 do you stop cats becoming infected?

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.

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

There are two options:

1. Rehome 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 injections?

Whether or not FIV-infected cats should receive routine vaccination is disputed. Stimulating the immune system by giving a vaccine may lead to progression of FIV infection by altering the balance between immune system and virus. However, FIV-infected cats are prone to acquiring infections and, therefore, protecting them from diseases such as cat flu may be beneficial. The potential benefits and risks of vaccinating FIV-infected cats should be weighed up in individual cats. Indoor cats which have been vaccinated within the last few years have a very low risk of acquiring infections, so booster vaccination is (probably) best avoided. Whereas in outdoor cats with risk of exposure to infections, vaccination is advised.

Although there in no evidence that FIV-infected cats are at increased risk from  modified live virus vaccines, inactivated vaccines are recommended whenever available as immune-suppressed cats may be at an increased risk of developing clinical disease if a modified live vaccine is administered.

Can I protect my cat with a vaccination against FIV?

At the moment there are no vaccines for FIV available in Europe. A vaccine for FIV is available in the USA although there is limited information concerning the efficacy of this product.

Updated November 2008