CATS · Condition guide
FIV and FeLV in cats: real veterinary cases
FIV and FeLV are two different retroviruses that attack the immune system, but their prognoses differ enormously. FIV-positive cats often live long, normal lives as indoor-only cats — the virus progresses slowly over years, and many FIV+ cats never develop clinical disease. FeLV is more serious: it can cause lymphoma, severe anaemia, and immune suppression, and historically had a poorer prognosis — though modern supportive care has improved outcomes.
Every new cat and kitten should be tested. SNAP combo tests (in-clinic) screen for both viruses simultaneously. A positive FIV result needs confirmation (Western blot or PCR) because false positives occur. A positive FeLV should be re-tested in 30-60 days, as many cats clear the virus. Understanding which virus your cat carries — and which stage they're in — determines everything.
What vets typically check for
- SNAP combo test (in-clinic): screens for FIV antibody + FeLV p27 antigen simultaneously.
- FIV-positive confirmation: Western blot, IFA, or proviral PCR to rule out false positive.
- FeLV-positive: re-test in 30-60 days (IFA or proviral PCR) to distinguish transient from persistent infection.
- Baseline bloodwork, urinalysis, and reticulocyte count — FeLV cats are prone to anaemia.
- Management: indoor-only lifestyle, regular (every 6-12 month) health checks, prompt treatment of any illness.
Not a replacement for veterinary care. Use this to walk into the conversation prepared, not to self-diagnose.
Real cases from the veterinary literature
Peer-reviewed reports our semantic search surfaces for FIV and FeLV. Click into any case for the full abstract — or run a personalised search with your pet's exact details.
- 2020 AAFP Feline Retrovirus Testing and Management Guidelines.
Journal of feline medicine and surgery · 2020 · Canada
Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are infections that can affect cats all over the world, leading to various health issues that can shorten their lives. It's important for cat owners to know if their pets are infected, as this helps prevent the spread of these viruses. Cats should be tested for these viruses when they are first adopted, after
- 2008 American Association of Feline Practitioners' feline retrovirus management guidelines.
Journal of feline medicine and surgery · 2008 · United States
Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are two common infections that can affect cats. While there are vaccines available for both, the best way to prevent new infections is to identify and separate infected cats. It's important for all cats to be tested for these viruses at certain times, like when you first get them, if they’ve been around an inf
- Diseases associated with feline leukemia virus and feline immunodeficiency virus infection: A retrospective study of 1470 necropsied cats (2010-2020).
Comparative immunology, microbiology and infectious diseases · 2023 · Brazil
This study looked at the health issues related to feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) in 1,470 cats that had died and been examined. Out of these, about 27% had FeLV, 14% had FIV, and 9% had both viruses. Cats with FeLV were more likely to develop cancers like lymphoma and leukemia, while those with both FeLV and FIV had a higher chance of getti
Frequently asked questions
- Can an FIV-positive cat live with other cats?
- Yes — FIV spreads primarily through deep bite wounds, not casual contact. In a stable, non-aggressive multi-cat household, the risk of transmission is very low. Many shelters and vets now recommend housing FIV+ cats with FIV-negative cats as long as they get along.
- Should I adopt an FIV+ or FeLV+ cat?
- FIV+ cats are excellent adoption candidates — most live normal lifespans. FeLV+ cats need more careful consideration: they may develop illness sooner, shouldn't share space with FeLV-negative cats, and need more frequent veterinary monitoring. But many live happy years with good care.
- Is there a vaccine?
- There's a vaccine for FeLV (recommended for kittens and at-risk cats). The FIV vaccine was discontinued in most markets because it caused false-positive test results without strong efficacy data. Prevention through indoor living and testing before introduction remains the primary strategy.