What is FIV?

Feline Immunodeficiency Virus (FIV) has been associated with cats for many years, although it was only labelled as such as recently as 1986. The virus depletes 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 enjoy a normal lifespan with no apparent health problems resulting from the virus.

FIV can only be transmitted from cat to cat, and 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. It can be known inaccurately as feline Aids, and this can strike a fear in an owner. So it is worth taking time to consider the facts.

How does a cat catch the virus?

The virus is present in the blood and saliva of infected cats. But, like HIV, it is a very 'fragile' virus, and cannot survive for long outside the body. It also requires a high dose to establish an infection in another cat. Therefore, it is not easily passed from cat to cat. The main route of infection is through biting, when virus in the saliva of an infected cat is injected directly into the blood stream of the cat it bites.

Cats that fight are most likely to be infected. Cat fights are most likely between entire toms and these are therefore the group most at risk. Since many feral cats are un neutered and have to compete for food, there is a higher incidence of FIV in feral cats. Transmission between cats in a group who do not fight is unlikely as the virus can only survive a very brief time outside a cat's body, and it cannot be transmitted indirectly, such as on food, feeding equipment, clothes, shoes, hands etc.

t has not been proved that the virus is transmitted sexually, although often the tom cat will hold onto the scruff of the female's neck with his teeth, so if the skin is punctured at that point, transmission is possible.

How do you prevent a cat from becoming infected?

If keeping them inside is not an option, as this is the only guaranteed way of preventing infection, then they must be neutered. This will prevent them from fighting, and getting bitten.

What are the signs of FIV?

• Raised lymph nodes around six to eight weeks after being infected.
• They may have a high temperature
• Sometimes diarrhoea or conjunctivitis may develop
• Gingivitis (gum inflammation)
• Sneezing, snuffling, a discharge from the nose or eyes
• Kidney failure

The commonest infection to occur in FIV positive cats is gingivitis and stomatitis (inflammation of the gums and other parts of the mouth).

What is their Life Expectancy?

A long-term FIV Monitoring Project was carried out at Glasgow Veterinary School over a number of years and the results indicated that a higher percentage of FIV negative cats died during the period of the study than FIV positive cats! A fourteen year study by Maureen Hutchison B.Sc, BVMS, MRCVS (veterinary adviser to the Cat Action Trust and to Cat Chat) found that FIV-positive cats are more likely to die by being killed in road accidents or to be alive and well into their twilight years than they are to die from any FIV related condition. Also, a recent survey by Dr Diane D. Addie (Lecturer in Veterinary Virology, University of Glasgow) where 26 cats were monitored for ten years, found that FIV infection did not affect the cats’ life expectancy.

Testing and Treatment

Testing: The FIV test routinely carried out in veterinary practices detects antibodies, which develop four to six weeks after infection, but this test is often unreliable as to whether the cat has the virus. Positive test results obtained by using this simple 'ELISA' test (sometimes called a CITE test, or 'COMBO' test,) should be confirmed by an IFA test (Immuno-Fluorescent Antibody Test) or a Western Blot, as quite often false positives can occur. Some of the ELISA tests are so inaccurate as to make the whole test meaningless, and are producing 'false positives' (due to reacting with a variety of other compounds in the cat's blood). According to the Glasgow Companion Animal Diagnostic Unit web-site (where they give the results of an on-going survey), up to 7% of positive results with the ELISA test are negative when checked by the more accurate IFA test. Many rescues have given up using the ELISA test, and are now using the IFA test only, saving time and money, whilst also being more accurate.

The IFA test is not expensive (usually about £25), and will give you a definitive answer in under a week. To obtain this ask your vet to send a blood sample to either Glasgow University's Companion Animal Diagnostics (Tel: 0141 330 5777), or to VetLab in West Sussex (Tel: 01403 730176), or University of Bristol's Langford Veterinary Diagnostics (Email: vet-path@bristol.ac.uk)

Very rarely, false negative results can occur if the test is done too early for antibodies to have developed, or simply because of the innacuracy of the ELISA test. Again the IFA test will confirm with far more accuracy.

Treatment: Treatment consists of dealing with whatever symptoms occur in the individual cat, such as common infections being treated with Antibiotics. If an FIV positive cat displays any symptoms of illness, however minor, it should be taken to a vet promptly. Once established in a cat's cells, the virus is permanent, and no proven vaccine* has yet been found.

*A vaccine was developed in the USA in 2002, but it is still too early to determine it's reliability. A big disadvantage with this vaccine is that once a cat has the vaccine, they will automatically test positive on an FIV test even though they don't have the virus.