FIV in Cats: Symptoms, Stages, Life Expectancy and Care

What a positive FIV test means, how the virus progresses, how long cats live with it, and which signs need a vet today or an ER now.

Quick answer: FIV (feline immunodeficiency virus) is a cat virus, spread mainly by bite wounds, that weakens the immune system over years. Many FIV-positive cats without FeLV live average lifespans, especially indoors with vet checkups at least every 6 months. Call a vet today for mouth pain, a fight wound, fever or 24 hours without eating. Go to an ER for labored breathing, collapse or straining with little or no urine.

This article is general information, not a diagnosis. If you think your pet is in danger, go to the nearest emergency animal hospital.

What FIV is, and what it is not

FIV is a virus that infects only cats. Over years it damages the white blood cells that fight infection, so other germs take hold more easily. The Cornell Feline Health Center estimates that about 2.5% to 5% of healthy cats in North America have FIV, and 15% or more of cats that are sick or at high risk.

• Not FeLV. Feline leukemia virus spreads more easily and has a more guarded outlook. The AAFP advises testing for both after a fight.
• Not FIP. FIP comes from a mutated feline coronavirus. The table further down compares all three.
• Not a risk to people or dogs. FIV infects only cats (Cornell, Merck Veterinary Manual).

When FIV becomes urgent: signs that need an ER now

Go to an emergency vet now for:

• Labored, fast or open-mouth breathing at rest
• Collapse, extreme weakness or a seizure
• Pale, white, blue or yellow gums (FIV raises the risk of blood disorders and lymphoma)
• Straining to pee with little or no urine. Cornell says a urinary blockage can kill in less than 24 to 48 hours, and males are at higher risk.
• A very high or very low temperature (see the cat fever guide for the numbers)
• Swallowing any human medicine: call ASPCA Animal Poison Control at (888) 426-4435 (a consultation fee may apply) or Pet Poison Helpline at (855) 764-7661 (a per-incident fee applies).

For signs that need a vet today or this week, see the symptoms table below.

How cats catch FIV

FIV spreads mainly through bite wounds, when an infected cat's saliva gets into the bite. Cornell says the cats at highest risk are unneutered males that go outdoors, especially fighters. The 2020 AAFP feline retrovirus guidelines also link older age, outdoor access and fighting to higher FIV rates.

Other routes matter much less. Infected mothers rarely pass FIV to kittens, though the risk is higher if the mother is infected while pregnant. Sharing bowls and grooming do not spread it efficiently, and mating is not a major route.

Indoor cats are lower risk, not zero risk: they can catch FIV from a housemate that bites. After any bite or abscess, see a vet that day, ask about FIV and FeLV testing, and plan retests at least 30 days later for FeLV and at least 60 days later for FIV (AAFP), because a new infection can test negative at first.

The three stages of FIV

Cornell and the AAFP describe three stages, and not every cat moves through all of them.

Stage	When	What you may see
Acute	1-3 months after infection	Mild fever, swollen lymph nodes, low energy; often missed
Silent	Months to many years	Usually looks healthy; bloodwork may show changes
Progressive	Years later, if ever	Repeat infections, gum and mouth disease, weight loss

Cornell calls the middle stage "asymptomatic," and some cats never leave it. The acute signs were recorded in research cats; the AAFP says they have not been reported in natural infection, probably because owners miss them.

FIV symptoms to watch at home

Most signs owners notice are other infections taking hold. Cornell lists repeat infections of the skin, eyes, urinary tract and upper airways, and says gum and mouth inflammation (gingivostomatitis) is common. The AAFP says cancer is about five times more common than in uninfected cats. Cornell says immune-related blood disorders are more likely, and seizures and behavior changes are possible.

Sign	Why it matters with FIV	What to do
Red gums, drooling, trouble eating	Gum and mouth disease is common	Vet today
Bite wound or swelling after a fight	Abscess risk; FIV/FeLV exposure	Vet today; ask about FIV/FeLV tests
Fever	Infections can hit harder	Vet today; ER if very high or very low (see fever page)
Eats nothing for 24 hours	Often mouth pain or infection	Call a vet same day; kittens sooner
Sneezing, eye or nose discharge	Repeat airway infections	Vet this week; today if not eating
Red, cloudy or squinting eye, or a change in pupil size	Eye problems are common	Vet today
Straining to pee, little or no urine	Blockage can kill in under 24-48 hours	ER now
Labored or open-mouth breathing	Serious infection or chest disease	ER now
Pale, white, blue or yellow gums	Possible blood disorder or cancer	ER now
Seizure or collapse	Nerve disease or severe illness	ER now
Slow weight loss	Often first sign of decline	Clinic this week
New lump or swollen glands	Cancer about 5 times more common	Clinic this week (see lump page)
Skin sores that won't heal, or diarrhea that keeps coming back	Chronic infection or parasites	Vet this week

A cat with mouth pain may want food but stop eating, so don't wait the full 24 hours when the mouth looks sore. New behavior changes, confusion or night yowling can come from FIV-related nerve disease or another illness, so book a clinic visit this week; see this guide to senior cat yowling at night. A cat that suddenly sleeps far more or hides may be getting sick and should see a vet this week, or the same day if it also seems hot or won't eat; see this guide to normal sleep vs lethargy in cats.

My cat just tested positive: what the result really means

• It is an antibody test. The AAFP says most cats make detectable antibodies within 60 days of infection; Cornell gives a range of 2 to 6 months.
• A first positive often needs confirming. False positives are more likely in low-risk, indoor-only cats, so the AAFP recommends confirming a positive in-clinic result with a different kind of test, usually at a lab (such as western blot), especially in those cats. PCR is sometimes used, but Cornell notes it can be wrong in either direction.
• Kittens under 6 months are a special case. They can carry antibodies from their mother's milk and test positive for months, though few are actually infected. Cornell advises retesting every 60 days until at least 6 months of age; a kitten still positive after that almost certainly has FIV.
• Vaccine history matters. A cat that was ever vaccinated against FIV can test positive on many in-clinic tests, in some cats for more than 7 years (AAFP).
• A negative has limits too. After the window period, negatives are generally reliable in healthy, low-risk cats (AAFP). But a recently exposed cat can test negative, so retest no sooner than 60 days after the last possible exposure; a sick or high-risk cat may need a later retest or a different test.

Next steps: ask whether to confirm the result, test for FeLV if that has not been done, test every cat in the home, and book a full exam, bringing any shelter paperwork. For a shelter cat's first days, see this guide to a newly adopted cat not eating, hiding or sneezing.

FIV life expectancy: what helps and what shortens it

Cornell says many FIV-positive cats live average lifespans if they are not also infected with FeLV. The AAFP says survival varies a lot and can be similar to that of cats without FIV.

In a large study the AAFP cites, of more than 1,000 FIV-positive cats, those not euthanized near diagnosis lived a median 4.9 years after their first test, versus 6.0 years for FIV-negative cats of the same age and sex. Those cats were a median 5 years old at testing, so 4.9 years is time after a test, not a lifespan.

These are linked to a shorter life:

• FeLV co-infection. In one small study cited by the AAFP, cats with both viruses had significantly shorter lives and more lymphoma.
• Severe illness. The outlook is worse after severe FIV-related illness or with ongoing fever and weight loss. With several serious infections or cancers at once, Cornell says survival is usually only a few months.
• Crowding and stress. In a 22-month sanctuary study, crowded, high-stress housing was linked to more illness and deaths, while FIV-positive cats living alone or with one other cat showed no FIV signs.

What helps is in the checklist below. When a late-stage cat keeps getting sick, this quality-of-life guide can help you and your vet weigh comfort and options.

Living with an FIV-positive cat: an indoor checklist

1. Checkups at least every 6 months, with close checks of the mouth, lymph nodes, eyes and skin, and a weight check every time.
2. Yearly bloodwork: a blood count (AAFP), plus chemistry and urinalysis (Cornell).
3. Indoors only, or outdoors only in a secure enclosure such as a catio. For a cat that can't adjust, your vet decides case by case (AAFP).
4. Spay or neuter to reduce roaming and fighting.
5. A complete, balanced diet with no raw meat, raw eggs or unpasteurized dairy.
6. Parasite control, plus heartworm prevention where heartworm is common. Your vet picks the products.
7. Prompt care for any illness. Cornell notes these cats may need longer or more intense treatment for infections. Supplements and "immune boosters" are not proven FIV treatments.
8. A calm home, with separate food, water, litter and resting spots for each cat.

FIV-positive cats can have dental care and surgery like other cats. Your vet decides whether antibiotics are needed around surgery; the AAFP advises them only for clear signs of immune suppression or a moderate-to-high contamination risk. Tell every vet, boarder and groomer that your cat is FIV-positive, and ask your vet before starting any new medicine or supplement.

Can an FIV-positive cat live with other cats?

Often, yes. In calm homes where cats do not fight, Cornell says there is little risk and the AAFP calls it "negligible," but it is not zero. In one 26-cat home with no fighting seen, FIV spread to 6 more cats over 10 years (that home also had FeLV). In a sanctuary housing 8 FIV-positive cats with 130 uninfected cats, no spread was recorded over several years.

• Test every cat; testing one as a stand-in is unreliable (AAFP).
• Neuter every cat, and give each one its own resources to reduce conflict.
• Introduce new cats slowly, and don't add one to a home where cats already fight.
• Separating cats is ideal but not always realistic; decide with your vet.

FIV survives only a few hours in most environments. Before a new cat moves in where an FIV-positive cat lived, Cornell advises cleaning and disinfecting or replacing bowls, bedding, litter boxes and toys.

FIV vs FeLV vs FIP

Virus	Main spread	Outlook
FIV	Bite wounds from fights	Often years of good health
FeLV	Saliva, grooming, shared bowls, mother to kittens	Guarded; vaccine exists
FIP	Cat coronavirus mutates inside one cat; FIP itself generally not contagious	Serious; see FIP page

FeLV usually has the more guarded outlook: in the AAFP-cited study, cats with progressive FeLV lived a median 2.4 years after diagnosis, versus 6.3 years for matched FeLV-negative cats.

Is there a cure, treatment or vaccine?

There is no cure (Cornell, Merck Veterinary Manual). Treatment targets secondary infections, mouth disease and other problems. Cornell says FIV antivirals are mostly borrowed from human HIV medicine: zidovudine (AZT) may help cats with severe mouth inflammation or nerve disease, but it has not been shown to extend survival and can have serious side effects. The AAFP says few controlled studies show lasting benefit from antivirals, so this is a decision for your regular vet after an in-person exam.

Never give a cat human medicine at home. If one is swallowed, call one of the poison lines listed above or go to an emergency vet.

No FIV vaccine has been sold in the US or Canada since the mid-2010s, though Cornell says it is still sold in some other countries. Prevention means indoor living, neutering and testing new cats.

What a video vet visit can and cannot do

First, emergencies: a cat with open-mouth or labored breathing at rest, collapse or a seizure, or that strains with little or no urine, needs an emergency vet now, not a video call.

If your cat just tested FIV positive, or a shelter told you your new cat is, a live video visit can help you plan next steps. If your cat is in Florida, New York or Virginia, you can book a $64.99 live video visit with Dr. Tiffany Delacruz, DVM, when a slot is open (about 8 AM-11 PM ET). She can review the result and shelter paperwork, explain whether to confirm it or retest (kittens especially), look at the gums, eyes and skin you show her, advise on housing the cat with your other cats, and give you a checkup plan to take to your local clinic.

A video visit does not replace the in-person exam a newly diagnosed cat needs. It cannot test for, confirm or rule out FIV, draw blood, take a temperature, drain an abscess or treat the mouth. There is no FIV medicine to promise; any prescription depends on the exam and state rules (see the FAQ below).

For homes with several pets, the one-time $120 Family Plan covers 4 visits over 12 months for every pet in the home and never auto-renews. Book a video visit.

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Frequently Asked Questions

How long can a cat live with FIV?

Often many years. Cornell says many FIV-positive cats live average lifespans if they don't also have FeLV, and good care such as indoor living and regular checkups helps. Survival varies a lot, and the outlook is worse with FeLV co-infection, repeated severe illness, or ongoing fever and weight loss.

Can FIV spread to humans or dogs?

No. FIV infects only cats, and there is no evidence it infects or causes disease in people (Cornell, Merck).

Is FIV the same as feline AIDS?

No. A confirmed positive test means the cat was infected, but signs of immune failure may take years to appear, if they ever do (VCA). VCA adds that feline AIDS is a name sometimes used for the illness signs FIV can cause, not for a positive test.

Should an FIV-positive cat be put down?

Not because of the diagnosis alone. The AAFP 2020 guidelines say a positive test should not be the only reason for euthanasia, and that confirmation testing should be offered because false positives are possible. VCA says euthanasia is generally not needed until the late stages.

Can I adopt an FIV-positive cat if I have other cats?

Often yes, in a calm home where the cats get along. The risk is low but not zero, so test every cat you have, neuter all of them, introduce the new cat slowly, and don't add a cat to a home where cats already fight.

My kitten tested FIV positive. Does it really have FIV?

Not necessarily. Kittens can carry their mother's FIV antibodies and test positive for months, but the AAFP says most test negative once those fade. Cornell advises retesting every 60 days until at least 6 months old; a kitten still positive after that almost certainly has FIV. A PCR test may clarify sooner, but it can be wrong either way.

What are the end-stage signs of FIV?

Infections that keep coming back, severe mouth disease, steady weight loss, ongoing fever, cancer such as lymphoma, pale gums, and seizures or behavior changes (Cornell, AAFP). Labored breathing, collapse, a seizure or pale gums need an emergency vet now.

Can FIV be handled on a video visit if my cat is in Florida, New York or Virginia?

Partly. A video visit cannot test for, confirm or rule out FIV; blood tests, the hands-on exam, dental treatment and abscess care need your local clinic. On camera, Dr. Delacruz can review results and paperwork, look at what you show her, and plan retesting, FeLV testing, housing and checkups. If medicine comes up: in Florida, after a video-only visit a vet can prescribe only FDA-approved animal drugs used as labeled, for up to 14 days (1 month for products labeled only for flea and tick control), with no renewal without an in-person exam, and no human drugs such as AZT, no controlled drugs, and no compounded anti-infectives such as antivirals or antibiotics. In all three states, federal rules require an in-person vet relationship for off-label or human-drug use. Virginia allows an electronic exam, but the federal rule still applies, and New York's rules are unsettled, so the vet will tell you what can be done by video. No prescription is guaranteed. RexVet is not a pharmacy, and a pharmacy transfer fee applies if an Rx is sent to an outside pharmacy.