Feline Immunodeficiency Virus (FIV) and Feline Leukaemia Virus (FeLV) are both retroviruses that attack a cat's immune system, but they behave differently and are transmitted in different ways. FIV is often compared to human HIV; it slowly weakens the immune system over many years, leaving the cat vulnerable to other infections.

FeLV, on the other hand, tends to progress more rapidly. In addition to suppressing the immune system, FeLV frequently causes severe anaemia and is a leading cause of feline cancers, particularly lymphoma and leukaemia.

Because the symptoms of both viruses can be vague and overlap significantly—such as lethargy, weight loss, and recurring minor infections—a reliable dual diagnostic test is the only way to know for sure which virus, if either, is affecting your cat.

FIV is primarily transmitted through deep bite wounds. The virus is shed in high concentrations in the saliva of an infected cat and is injected directly into the bloodstream of another cat during aggressive fights. Therefore, unneutered outdoor male cats are at the highest risk. It is rarely spread through casual contact like sharing food bowls or mutual grooming.

FeLV is much more easily transmitted through close, casual contact. It is spread via saliva, nasal secretions, urine, and faeces. Cats can catch FeLV from mutual grooming, sharing food and water bowls, or using the same litter tray. It can also be passed from an infected mother cat to her kittens in the womb or through her milk.

Understanding these transmission routes is crucial. If you are bringing a new cat into your home, testing them first is a vital step in protecting your existing pets.

Yes, obtaining a blood sample from a cat at home can be challenging, which is why this kit is primarily intended for use by veterinary professionals or highly experienced pet owners. Cats have thick skin and fur, and they rarely sit still for a needle prick.

If you are testing at home, you will need a separate lancing device and sterile lancets (similar to those used for diabetic blood glucose testing). The easiest places to get a small drop of blood are usually the edge of the ear (the marginal ear vein) or a paw pad.

If you are not confident in your ability to safely and cleanly obtain a blood sample without causing your cat undue stress, we strongly recommend taking the kit to your vet and asking them to perform the blood draw for you.

The test cassette has two separate reading windows: one labelled FIV and one labelled FeLV. Each window works independently. You must read the results at exactly 10 minutes.

In each window, a coloured line should appear in the Control zone ('C'). This confirms the test has run correctly. If a second coloured line appears in the Test zone ('T'), the result is positive for that specific virus. For example, if you see a 'T' line on the FIV side but not the FeLV side, your cat is positive for FIV only.

If no 'C' line appears in a window, that specific test is invalid, usually due to an insufficient blood sample or an error in adding the buffer solution. For more guidance on interpreting results, see our tips for accurate testing.

Yes, it is entirely possible for a cat to be co-infected with both Feline Immunodeficiency Virus and Feline Leukaemia Virus simultaneously. This is why a combo test is so valuable.

Cats with both viruses face a much poorer prognosis than those with only one. Their immune systems are under severe, double attack, making them extremely susceptible to secondary infections, severe anaemia, and certain types of cancer.

If your cat tests positive for both viruses, immediate and intensive veterinary consultation is required to discuss their quality of life and the most appropriate management plan moving forward.

A positive result for either FIV or FeLV is serious, but it is not necessarily an immediate death sentence. Many cats, particularly those with FIV, can live for years without showing severe symptoms if they are managed correctly.

First, you must contact your vet to confirm the diagnosis, often with a secondary laboratory test. Once confirmed, the most important step is to keep the infected cat strictly indoors. This protects them from catching secondary infections from other animals, and crucially, prevents them from spreading the virus to healthy cats in the neighbourhood.

Infected cats require a high-quality diet, stress reduction, and frequent veterinary check-ups (at least twice a year) to catch and treat any secondary infections—like urinary tract infections or digestive issues—as early as possible.

No. Both Feline Immunodeficiency Virus and Feline Leukaemia Virus are strictly species-specific. They can only infect felines.

You cannot catch FIV or FeLV from your cat, nor can your dog or any other non-feline pets in your household. While FIV is similar in structure to human HIV, the virus cannot bind to human cells and poses absolutely zero risk to human health.

However, because an infected cat has a weakened immune system, they may be more susceptible to carrying other secondary infections (like certain bacteria or parasites) that *could* potentially be zoonotic (transmissible to humans). Good hygiene, such as washing hands after cleaning the litter tray, remains important.

Testing kittens requires careful timing. For FeLV, kittens can be tested at any age. If they acquired the virus from their mother, they will typically test positive. However, a negative result in a very young kitten should be reconfirmed a few months later.

For FIV, the situation is more complex. The FIV portion of the test looks for *antibodies*, not the virus itself. Kittens born to an FIV-positive mother may absorb her antibodies through her milk and test 'false positive' for up to 6 months, even if they aren't actually infected.

Therefore, if a kitten under 6 months old tests positive for FIV, they should not be euthanised or permanently labelled as infected. They must be retested after they reach 6 months of age, by which time the maternal antibodies will have cleared from their system.

This is a very important consideration. The FeLV portion of this test detects the viral antigen, so a cat vaccinated against FeLV will NOT test positive simply because they had the vaccine.

However, the FIV portion detects antibodies. Historically, there was an FIV vaccine available in some countries (though it is rarely used in the UK now). Cats that received this vaccine will produce antibodies and will test positive on this rapid test, making it impossible to distinguish between a vaccinated cat and a genuinely infected cat without complex laboratory PCR testing.

Always check your cat's vaccination history if possible. If you know they have had an FIV vaccine in the past, this rapid test will not be able to give you an accurate diagnosis for FIV.