Last updated: April 27, 2026

FIV and FeLV in Cats: What Every Owner Should Know

Few diagnoses worry cat owners more than FIV or FeLV. These two viral infections — feline immunodeficiency virus and feline leukemia virus — affect millions of cats worldwide, and the stigma surrounding them leads to countless otherwise-healthy cats being overlooked in shelters. The truth is that a cat FIV FeLV diagnosis does not have to be a death sentence. With proper understanding, veterinary care, and management, many infected cats live long, comfortable, and fulfilling lives.

Whether you are a current cat owner concerned about your pet’s health, considering adopting a shelter cat, or simply want to educate yourself about these common feline viruses, this guide covers everything you need to know — from how these diseases spread and are diagnosed to treatment options, prevention strategies, and what daily life looks like for cats living with FIV or FeLV.

What Is FIV in Cats?

Feline immunodeficiency virus, commonly known as FIV, is a lentivirus that attacks a cat’s immune system. It is sometimes called “cat AIDS” because it is structurally similar to HIV in humans, though it is important to understand that FIV cannot be transmitted to humans or other non-feline animals. The virus specifically targets white blood cells called CD4+ T-lymphocytes, gradually weakening the immune system over time.

FIV progresses through three distinct phases:

1. Acute phase (weeks to months): Shortly after infection, the cat may experience a brief period of mild illness including fever, swollen lymph nodes, and lethargy. Many owners do not even notice these symptoms, as they tend to resolve on their own.
2. Asymptomatic or latent phase (years to a lifetime): This is the longest stage. The virus is present in the cat’s body but causes no visible symptoms. Some cats remain in this phase for their entire lives and never progress to the clinical stage. This phase can last anywhere from several years to well over a decade.
3. Clinical phase: If the immune system becomes sufficiently compromised, the cat becomes vulnerable to secondary infections, chronic illnesses, and certain cancers. Not all FIV-positive cats reach this stage.

It is estimated that 2.5 to 5 percent of cats in the general population are FIV-positive, with higher rates among outdoor, unneutered males due to their tendency to fight. The key takeaway for owners is that FIV is a manageable condition. Many FIV-positive cats live just as long as their uninfected counterparts when given proper indoor care and regular veterinary attention.

What Is FeLV in Cats?

Feline leukemia virus, or FeLV, is a retrovirus that integrates itself into a cat’s DNA and can affect nearly every organ system in the body. It is one of the most common infectious causes of disease and death in domestic cats. Unlike FIV, which primarily weakens the immune system, FeLV can cause a wider range of serious conditions including anemia, lymphoma and other cancers, immune suppression, and reproductive problems.

When a cat is exposed to FeLV, one of several outcomes may occur:

• Abortive infection: Cats with strong immune systems may fight off the virus entirely and never become infected. This is more common in healthy adult cats.
• Regressive infection: The cat’s immune system controls the virus, which becomes dormant in the bone marrow. These cats typically test negative on standard blood tests but may still harbor the virus at low levels. Reactivation is possible under severe stress or immune suppression.
• Progressive infection: The virus overwhelms the immune system and actively replicates in the bone marrow and blood. These cats remain persistently viremic (virus present in the blood), shed the virus, and are most likely to develop FeLV-related diseases.

FeLV is generally considered more serious than FIV. Cats with progressive FeLV infections have a median survival time of about 2.5 years after diagnosis, though some cats live significantly longer with excellent care. Kittens are particularly vulnerable because their immature immune systems are less capable of fighting off the virus.

How FIV and FeLV Spread

Understanding how cat FIV FeLV infections are transmitted is essential for prevention. While both are viral infections, they spread through different mechanisms.

FIV transmission:

• Bite wounds: This is by far the primary route of FIV transmission. The virus is present in high concentrations in saliva, and deep bite wounds effectively inject the virus into the bloodstream. This is why intact male cats that roam and fight are at the highest risk.
• Mother to kitten: Vertical transmission from an infected mother to her kittens during birth or through nursing is possible but relatively uncommon.
• Casual contact: FIV is not transmitted through casual contact such as sharing food bowls, mutual grooming, or using the same litter box. The virus is fragile outside the body and does not survive long in the environment.

FeLV transmission:

• Prolonged close contact: FeLV spreads primarily through saliva, nasal secretions, urine, feces, and milk. Mutual grooming, sharing food and water dishes, and sharing litter boxes are all common routes of transmission.
• Bite wounds: Like FIV, bite wounds can transmit FeLV, though casual contact is a more common route for this virus.
• Mother to kitten: An infected mother cat can transmit FeLV to her kittens in utero, during birth, or through nursing. This is a significant route of transmission.
• Environmental survival: FeLV is more resilient than FIV outside the body but still relatively fragile. It can survive in damp environments for a few hours but is easily killed by disinfectants, drying, and sunlight.

Neither FIV nor FeLV can be transmitted to humans, dogs, or other non-feline species. These are strictly feline viruses.

Testing for FIV and FeLV

Routine testing for FIV and FeLV is a critical part of responsible cat ownership. Most veterinarians recommend testing every cat at least once in its lifetime, and many recommend testing in specific situations including when you first acquire a new cat, after any known exposure to an infected cat, when a cat is sick with signs consistent with these infections, and before introducing a new cat to a multi-cat household.

The standard screening test is a combination SNAP test (also called an ELISA test) that can be performed in your veterinarian’s office with results available in about 10 minutes. This test requires only a small blood sample and screens for both viruses simultaneously.

• For FIV: The SNAP test detects antibodies to FIV. A positive result means the cat has been exposed to the virus and has mounted an immune response. However, false positives can occur, particularly in kittens who received maternal antibodies from a vaccinated or infected mother. Kittens that test positive should be retested after six months of age.
• For FeLV: The SNAP test detects FeLV p27 antigen in the blood, indicating active viral presence. A positive result should always be confirmed with a secondary test.

Confirmatory testing is recommended for all positive results. The IFA (immunofluorescent antibody) test and PCR (polymerase chain reaction) test can confirm infection and help distinguish between progressive and regressive FeLV infections. Your veterinarian will advise which confirmatory tests are appropriate based on the initial results.

It is important to note that there is a window period after exposure during which a cat may test negative despite being infected. For FIV, antibodies typically become detectable 2 to 4 weeks after infection but may take up to 60 days. For FeLV, antigen may be detectable as early as a few days after infection, but retesting in 30 to 60 days is recommended after a known exposure.

Symptoms of FIV and FeLV

Both FIV and FeLV can remain asymptomatic for extended periods, making regular testing all the more important. When symptoms do appear, they often reflect the secondary conditions that arise from immune suppression rather than the virus itself.

Common symptoms of FIV include:

• Recurrent upper respiratory infections (sneezing, nasal discharge, eye discharge)
• Chronic or recurrent mouth and gum infections (stomatitis and gingivitis) — this is one of the most common clinical signs
• Persistent diarrhea
• Poor coat condition and chronic skin infections
• Slow wound healing
• Unexplained weight loss and decreased appetite
• Fever that comes and goes
• Swollen lymph nodes
• Eye problems including inflammation of the iris (uveitis)
• Neurological issues in advanced cases (behavioral changes, seizures)

Common symptoms of FeLV include:

• Progressive weight loss and loss of appetite
• Pale gums and mucous membranes (a sign of anemia)
• Enlarged lymph nodes
• Recurrent infections of the skin, bladder, and upper respiratory tract
• Persistent fever
• Chronic diarrhea
• Difficulty breathing
• Reproductive problems including infertility and abortion in females
• Jaundice (yellowing of the whites of the eyes and gums)
• Tumors or masses, particularly in the chest or abdomen (lymphoma)
• Neurological signs including hind-limb weakness and uncoordinated movement

If your cat shows any of these symptoms, schedule a veterinary examination promptly. Early detection and intervention can make a significant difference in outcomes for cats with FIV or FeLV.

Treatment and Management of FIV and FeLV

There is currently no cure for FIV or FeLV. Treatment focuses on managing symptoms, preventing secondary infections, and maintaining the best possible quality of life. With conscientious management, many infected cats thrive for years.

General management strategies for both conditions include:

• Regular veterinary checkups: FIV-positive and FeLV-positive cats should see the vet at least twice a year for comprehensive wellness exams. These visits should include bloodwork to monitor immune function, organ health, and blood cell counts.
• High-quality nutrition: A well-balanced, nutritionally complete diet supports immune function. Some veterinarians recommend high-protein diets for immune-compromised cats. Avoid raw or undercooked meat and eggs, as the risk of foodborne pathogens is higher for cats with weakened immune systems.
• Prompt treatment of secondary infections: Any signs of illness should be addressed quickly, as infections that would be minor in a healthy cat can become serious in an immunocompromised one. Antibiotics, antifungals, and supportive care are used as needed.
• Parasite prevention: Maintain regular flea, tick, and intestinal parasite prevention. Parasites place additional stress on the immune system.
• Dental care: Oral health issues are extremely common in FIV-positive cats. Regular dental cleaning and prompt treatment of gingivitis or stomatitis is essential.
• Stress reduction: Chronic stress suppresses the immune system. Provide a calm, enriched environment with hiding spots, vertical spaces, consistent routines, and plenty of interactive play.
• Keeping cats indoors: Indoor living protects infected cats from exposure to additional pathogens and prevents them from spreading the virus to other cats.

FeLV-specific treatments may include antiviral medications, blood transfusions for severe anemia, chemotherapy for FeLV-associated lymphoma, and immunomodulatory drugs. Your veterinarian will tailor a treatment plan based on your cat’s specific condition and progression.

FIV-specific management often centers on dental care, as stomatitis is one of the most debilitating complications. In severe cases, full-mouth tooth extraction can dramatically improve quality of life for cats with FIV-related stomatitis. While this sounds extreme, most cats adapt remarkably well and are finally free from chronic oral pain.

Can FIV and FeLV Cats Live Normal Lives?

This is one of the most important questions cat owners and potential adopters ask, and the answer — especially for FIV — is overwhelmingly positive.

FIV-positive cats can absolutely live normal, full-length lives. Multiple studies have shown that indoor FIV-positive cats with regular veterinary care have lifespans comparable to uninfected cats. Many FIV-positive cats live well into their teens. The virus progresses slowly, and with proper management, the asymptomatic phase can last the cat’s entire natural lifetime. FIV-positive cats play, purr, cuddle, and enjoy life just like any other cat.

FeLV-positive cats face a more challenging prognosis, but even here the outlook is not as dire as many people believe. While the median survival time for cats with progressive FeLV is about 2.5 years, some cats live significantly longer — 5 years or more is not uncommon with excellent care. Quality of life during these years can be very good, with many FeLV-positive cats enjoying active, comfortable lives between health episodes.

The biggest barrier to a normal life for FIV and FeLV cats is often not the virus itself but the misconceptions surrounding it. Too many healthy, vibrant cats are euthanized or languish in shelters simply because of a positive test result. Education and awareness are changing this, but there is still a long way to go.

Adopting an FIV-Positive or FeLV-Positive Cat

If you are considering adopting a cat, do not overlook FIV-positive or FeLV-positive cats. These animals are among the hardest to place in shelters, yet they can make wonderful, loving companions. Here is what you should know before adopting.

Benefits of adopting an FIV+ or FeLV+ cat:

• You are saving a life: Positive-testing cats are often the last to be adopted and the first to be euthanized in overcrowded shelters. By choosing one of these cats, you are giving a deserving animal a second chance.
• They are just as affectionate: FIV and FeLV do not affect a cat’s personality. These cats are just as playful, loving, and full of character as any other.
• Veterinary costs are often manageable: While you should budget for twice-yearly vet visits and potential treatment of secondary infections, many FIV-positive cats require no more medical care than the average cat for years after diagnosis.
• Reduced adoption fees: Many shelters and rescues offer reduced adoption fees for FIV-positive and FeLV-positive cats to encourage their placement.

What to consider before adopting:

• Are you prepared for the possibility of increased veterinary visits and costs, particularly as the cat ages?
• Can you commit to keeping the cat indoors for its entire life?
• If you have other cats, are they tested and, in the case of FeLV, vaccinated? (FIV-positive cats can often live safely with FIV-negative cats if they have a non-aggressive temperament.)
• Are you comfortable with the emotional aspect of potentially losing a pet to a chronic illness?

Many rescue organizations, including those listed in our cat breeds directory, specialize in placing FIV and FeLV cats and can provide guidance and support throughout the adoption process and beyond.

Prevention: Vaccination and Keeping Cats Indoors

Preventing FIV and FeLV infection is always preferable to managing it. Two key strategies form the foundation of prevention: vaccination and indoor living.

FeLV vaccination:

An effective FeLV vaccine is widely available and is considered a core vaccine for kittens by the American Association of Feline Practitioners (AAFP). The standard protocol includes an initial series of two doses given 3 to 4 weeks apart starting at 8 weeks of age, followed by a booster one year later. After the initial series, revaccination is recommended annually for cats at risk of exposure (outdoor cats, cats in multi-cat households, or cats with potential contact with FeLV-positive cats). Low-risk indoor-only cats may not need ongoing boosters after the first year, though this should be discussed with your veterinarian.

The FeLV vaccine is highly effective but not 100 percent protective. It significantly reduces the risk of infection but does not eliminate it entirely, which is why combining vaccination with other prevention measures is important.

FIV vaccination:

An FIV vaccine was previously available in the United States but was discontinued in 2017. The vaccine had several limitations — it did not protect against all FIV strains, and vaccinated cats tested positive on standard FIV antibody tests, making it impossible to distinguish vaccinated cats from truly infected ones. Currently, there is no FIV vaccine available in most countries, making behavioral prevention strategies all the more critical.

Keeping cats indoors:

Indoor living is the single most effective way to prevent both FIV and FeLV infection. Cats that never go outside and never encounter unknown cats have virtually zero risk of contracting either virus. If you want to give your indoor cat outdoor experiences, consider a secure catio (enclosed outdoor space) or leash-training, both of which allow outdoor enjoyment without the risks of free roaming.

Additional prevention tips:

• Spay or neuter all cats. Intact males are far more likely to roam, fight, and both transmit and contract FIV.
• Test all new cats before introducing them to your household.
• If you foster cats, keep foster cats separated from your resident cats until test results are confirmed.
• If your cat must go outside, supervise outdoor time and avoid areas where stray or feral cats congregate.

FIV and FeLV in Multi-Cat Households

Managing FIV or FeLV in a multi-cat household requires careful planning, but it is absolutely possible to keep both positive and negative cats safe and happy under the same roof.

FIV in multi-cat households:

Because FIV is primarily transmitted through deep bite wounds, FIV-positive cats can often live safely with FIV-negative cats as long as the cats get along and do not fight. Many rescue organizations and veterinary experts now support mixed-status FIV households provided the cats are properly introduced and have non-aggressive temperaments. Key considerations include:

• Introduce cats slowly and carefully using standard introduction protocols (scent swapping, visual barriers, supervised meetings).
• Monitor interactions and separate cats if aggression or rough play occurs.
• Provide enough resources (food bowls, water stations, litter boxes, resting spots) to minimize competition and conflict.
• Sharing food bowls and grooming between cats is generally considered low-risk for FIV transmission.
• All cats should be spayed or neutered, which significantly reduces aggressive behavior.

FeLV in multi-cat households:

FeLV requires more caution because it spreads through casual contact including shared bowls and mutual grooming. If you have an FeLV-positive cat in a multi-cat household:

• All FeLV-negative cats should be vaccinated against FeLV before any contact occurs.
• Ideally, FeLV-positive cats should be kept in a separate area with their own food bowls, water dishes, and litter boxes.
• If complete separation is not possible, vaccination of all negative cats is essential, though no vaccine provides 100 percent protection.
• Some owners choose to keep only FeLV-positive cats together, creating a household where all cats share the same status.
• Regular testing of all cats in the household is recommended — at least annually for FeLV-negative cats living with FeLV-positive cats.

Consult your veterinarian about the best arrangement for your specific household. Every situation is different, and your vet can help you develop a management plan that keeps all your cats as safe as possible. You can also explore our cat breeds directory to research breed-specific health considerations when building your feline family.

Frequently Asked Questions

Can humans catch FIV or FeLV from cats?

No. FIV and FeLV are species-specific viruses that affect only cats. They cannot be transmitted to humans, dogs, or any other non-feline species. You can safely handle, cuddle, and care for an FIV-positive or FeLV-positive cat without any risk to your own health.

How long can an FIV-positive cat live?

With proper indoor care and regular veterinary attention, many FIV-positive cats live into their teens — a lifespan comparable to uninfected cats. The asymptomatic phase of FIV can last the cat’s entire lifetime. Some FIV-positive cats never develop clinical disease at all.

Is FeLV always fatal?

Not necessarily. While FeLV is a serious diagnosis with a shorter median survival time than FIV, some cats with progressive FeLV live 5 or more years with excellent care. Additionally, some cats mount a strong enough immune response to achieve a regressive infection, where the virus is controlled and clinical disease may never develop.

Should I euthanize my cat if it tests positive for FIV or FeLV?

Absolutely not, unless the cat is already suffering from advanced, untreatable disease. A positive test result alone is never a reason for euthanasia. Many FIV-positive cats and some FeLV-positive cats live long, comfortable lives with proper care. Discuss your cat’s specific prognosis and care plan with your veterinarian.

Can FIV-positive and FIV-negative cats live together?

Yes, in most cases. Since FIV is transmitted primarily through deep bite wounds, cats that coexist peacefully pose minimal risk to each other. Proper introductions, adequate resources, and spaying or neutering all cats are important steps. Many multi-cat households include both FIV-positive and FIV-negative cats without issues.

Is there a vaccine for FIV?

Not currently. An FIV vaccine was available in the United States until 2017 but was discontinued due to limited efficacy and because it caused vaccinated cats to test positive on standard screening tests. The best prevention for FIV is keeping cats indoors and neutering males to reduce roaming and fighting behavior.

How much does it cost to care for an FIV or FeLV-positive cat?

Routine care costs are similar to those for any cat, with the addition of twice-yearly veterinary checkups instead of annual visits. Costs increase if secondary infections or complications arise, but many positive cats go years without needing any special treatment. Pet insurance that covers pre-existing conditions is becoming more available and may be worth exploring.

Can kittens be born with FIV or FeLV?

Kittens can acquire FeLV from their mothers during pregnancy, birth, or nursing, which is a significant route of transmission. FIV transmission from mother to kitten is less common but does occur. All kittens born to positive mothers should be tested, with retesting at appropriate intervals since maternal antibodies can cause false positive FIV results in young kittens.

If you are ready to open your heart and home to a cat in need — whether FIV-positive, FeLV-positive, or negative — visit our adoption page to browse available cats looking for their forever families.