What is FIV (feline immunodeficiency virus)?
Updated By PetymFacts checked against official sources on
Quick answer
FIV, feline immunodeficiency virus, is a lifelong virus of cats that slowly weakens the immune system. It spreads mainly through deep bite wounds, so unneutered males that roam and fight are most at risk. There is no cure, but many FIV cats live normal, healthy lives for years with good care. It cannot infect people.
Also called FIV, feline immunodeficiency virus, feline AIDS, cat AIDS.
Key facts
- The main way FIV spreads is through bite wounds from an infected cat; sharing bowls and grooming are not efficient routes. Cornell University College of Veterinary Medicine
- Infection is much more common in outdoor cats and about twice as common in males as in females. International Cat Care
- Cats infected with FIV can live very normal, healthy lives for many years if managed well. Cornell University College of Veterinary Medicine
- Kittens born to infected mothers can test positive for several months from her antibodies, so they are retested. Cornell University College of Veterinary Medicine
- FIV only affects cats; it cannot be passed to humans or other animals. International Cat Care
How do cats get FIV?
Almost always from a bite. The virus is in an infected cat's saliva and enters the bloodstream through a deep bite wound, which is why fights between unneutered tomcats over territory spread it most. Cats that live calmly together rarely pass it on by sharing bowls or grooming each other, and an infected mother only rarely passes it to her kittens.
Petym found no published national figure for how common FIV is in Indian cats. The risk pattern is the same everywhere: a cat that roams outdoors, is not neutered and gets into fights is the one most likely to meet it.
What happens after a cat is infected?
FIV moves slowly. Many cats spend years in the middle stage without any sign of illness.
1 to 3 months after infection
A mild first phase: swollen lymph nodes, sometimes fever, low mood or poor appetite. It is often missed. Cornell University College of Veterinary Medicine
Months to years
A long phase with no signs. Some cats never move beyond it. Cornell University College of Veterinary Medicine
Often around 2 to 5 years after infection
Signs may start to appear as the immune system weakens. International Cat Care
Later stage
Repeated infections of the skin, eyes, bladder or airways, sore gums, and a higher risk of cancer. Most illness comes from these, not from the virus itself. Cornell University College of Veterinary Medicine
How is FIV diagnosed?
With a blood test at the vet clinic that looks for antibodies to the virus. A cat infected only recently may still test negative, so a retest after at least 60 days is advised when exposure is possible. Kittens born to an FIV mother can carry her antibodies and test positive for months; Cornell advises retesting them every 60 days until six months old.
A vaccine exists in a few countries, but WSAVA notes it is available only in Japan, Australia and New Zealand, and vaccinated cats can test positive on common antibody tests. Avoiding bites is the best prevention.
How do you care for an FIV positive cat?
Keep the cat indoors, which protects it from infections and protects other cats from bites. Neutering cuts roaming and fighting. Cornell advises wellness checks at least every six months and prompt treatment of any illness, because a cold or a sore mouth matters more to a cat with a weakened immune system.
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Questions owners ask
Can humans catch FIV from cats?
- No. FIV only affects cats and cannot be passed to humans or other animals. Cornell adds that there is currently no evidence FIV can infect or cause disease in humans. You can stroke, feed and care for an FIV positive cat without any risk to yourself.
How long can a cat live with FIV?
- Many years. Cornell says cats infected with FIV can live very normal, healthy lives for many years if managed well. The outlook is less good once a cat has had severe illness, persistent fever or weight loss, which is why regular checks and quick treatment matter.
Can an FIV positive cat live with other cats?
- Often yes, if the cats are calm together and do not fight, because FIV spreads mainly through deep bite wounds rather than sharing bowls or grooming. Introduce new cats carefully, keep all cats neutered and indoors, and ask your vet about testing the other cats in the home.
My kitten tested positive for FIV. Does it have FIV?
- Not necessarily. Kittens born to infected mothers can carry her antibodies and test positive for several months after birth. Cornell advises retesting at 60-day intervals until the kitten is six months old before deciding it is infected.
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Related terms
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- Chronic kidney diseaseChronic kidney disease (CKD) is a slow, lasting loss of kidney function, common in older cats and also seen in older dogs. Early on there are often no signs; later a pet drinks and urinates more, eats less and loses weight. It cannot be cured, but a kidney diet, water and regular checks can slow it.
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Sources
Each source was opened and read on the date shown. How Petym checks its sources
- Cornell University College of Veterinary Medicine: Feline immunodeficiency virus (Cornell Feline Health Center) (opens in a new tab)
- International Cat Care: Feline immunodeficiency virus (FIV) (opens in a new tab)
- WSAVA: 2024 guidelines for the vaccination of dogs and cats (WSAVA Vaccination Guidelines Group, Journal of Small Animal Practice) (opens in a new tab)