What You Need to Know About FIV in Cats


Bryan Huynh

- Updated February 23, 2024

What You Need to Know About FIV in Cats

FIV, also known as Feline Immunodeficiency Virus, is a virus that can seriously weaken a cat's immune system. In this guide, we'll provide you with all the important information about FIV and how you can ensure the well-being of your cat, including tips on how to protect your cat.

FIV: What It Is

FIV (feline immunodeficiency virus) is a feline-only retrovirus belonging to the lentivirus subfamily, a type of virus with a long incubation period. This virus, first discovered in the 1980s, infects and damages the cells of the immune system and eventually compromising the immune system, making it difficult for the cat to fight off secondary infections from bacteria, viruses, and fungi; it can lead to feline AIDS (acquired immune deficiency syndrome), which is similar to AIDS in humans, but in some cases, it may never progress to AIDS. Different strains of the virus may be more harmful than others.

FIV can progress so slowly that cat owners often do not even notice when a cat's immune system is initially affected. FIV is not an automatic death sentence. Many times, cats will remain symptom-free for years and some can have a long and happy life as an uninfected cat.

Life expectancy for cats with FIV is difficult to determine since cats fall ill due to a compromised immune system or live a long life free of any complications. There is also the possibility they could end up with secondary infections that are chronic, recurrent, or prolonged.

FIV isn't easily transmittable between cats and is typically spread through bite wounds and close contact. It's most commonly seen in outdoor male cats who are not neutered since they are more likely to fight over territory and spread the infection through saliva and blood. It's unlikely for FIV to be spread through casual contact (since the organism can't live outside the body for very long) and even rarer for it to be spread through mating or birth; however, kittens can also become infected through their mothers before, during, or after birth (or while nursing), but many are able to fight it off before they reach six months of age.

FIV has 3 stages:

  • Initial infection/acute phase, in which cats may initially experience symptoms such as weight loss, lack of appetite, enlarged lymph nodes, and transient fever.
  • During the asymptomatic phase, which occurs after the initial infection, cats may show no signs of FIV for several years, even living a long and normal life like cats not affected with FIV. Eventually, their immune system may become further compromised.
  • Potential clinical phase, which is when a cat's immune system is damaged by FIV. They may suffer from chronic inflammatory conditions, secondary infections, cancer, kidney disease, and/or tumors.


Common symptoms of FIV in cats can include some or all of the following:

  • Loss of appetite
  • Weight loss
  • Anemia
  • Enlarged lymph nodes, which is a result of the virus being carried there and reproducing in the white blood cells, and may be hard to spot
  • Chronic infections of the skin, eyes, bladder, and upper respiratory tract
  • Frequent urination, difficulty urinating, or urinating outside the litter box
  • Diarrhea
  • Vomiting
  • Inflammation of gums or mouth
  • Persistent fever
  • Poor coat condition such as skin redness or hair loss
  • Behavioral changes or neurological disorders
  • Seizures
  • Eye conditions such as the inflammation of the membrane surrounding the eyes (chronic conjunctivitis) and discharge from the eyes
  • Gum and mouth inflammation (gingivitis/stomatitis)
  • Wounds that don't heal
  • Sneezing and discharge from nose

These symptoms may not appear for years, or may temporarily subside for a time before reappearing.


If you notice any of the symptoms mentioned above in your cat, it's important to act swiftly and take them to the veterinarian for testing. While these symptoms could potentially indicate FIV, they may also be linked to other underlying conditions or even unrelated issues.

When you visit the vet, make sure to provide a detailed account of all the symptoms you have observed in your cat, no matter how minor they may seem. It's also helpful to inform the vet about whether your cat has had any outdoor exposure and if there have been any situations where they might have come into contact with an infected cat.

To diagnose FIV, blood tests are conducted to detect virus antibodies. The most commonly used test is the ELISA (enzyme-linked immunosorbent assay) test. This test can determine if your cat has developed antibodies to the virus and whether they are currently infected.

These tests are not 100% accurate and may have a false positive or negative so a second positive screening test is necessary to confirm a diagnosis. Veterinarians can perform a more definitive test to determine a positive diagnosis through a Western Blot test, PCR (polymerase chain reaction, which detects short segments of the virus's genetic material), or immunofluorescence assay (IFA).

Note: false positives can occur if a cat is young or has been vaccinated against FIV since they can carry antibodies and the test doesn't distinguish between maternal, vaccine, or infection antibodies. With kittens, they can be re-tested when they are six months of age when the maternal antibodies are gone.

Additionally, cats may test negative if they haven't developed FIV antibodies yet; if you believe your cat may have been exposed to FIV, they can be tested after 8 to 12 weeks (when cats typically develop FIV antibodies).

On rare occasions, cats who are in the late stages of FIV can test negative for antibodies since their immune systems are compromised and may not produce a substantial amount of antibodies.

Treatment & Management


Once a cat is infected with FIV, they will have to deal with it for the rest of their life.

Luckily, many cats infected with FIV are able to live long and happy lives; FIV-infected cats don't need to be euthanized unless they are in the late stages and severely ill when treatment won't help their condition.

Here are some steps you can take to care of your cat and better manage their illness:

  • Take your cat to appointments regularly. It's essential your cat has a physical every six months with their veterinarian to keep track of their overall health, along with an annual blood count, biochemistry analysis, urinalysis, and fecal examination.
  • Keep track of their weight and monitor them for any signs of weight loss.
  • Monitor your cat's behavior for any sudden changes (and visit the veterinarian if needed). Cats infected with FIV may use the same medication and treatment as cats without FIV but might require additional medication or longer treatment.
  • Make sure they are spayed or neutered.
  • Feed them nutritious food and make sure they have a high quality, balanced diet. Avoid raw meat, eggs, unpasteurized dairy, and other uncooked food to reduce the possibility of catching a food-borne bacterial or parasitic infection, which is higher in immunocompromised cats.
  • Keep your cat indoors to reduce their exposure to dangerous organisms and to prevent the spread of FIV to any outdoor cats.
  • Since they'll be spending so much time indoors, make sure to minimize stress and treat them with plenty of toys, cat furniture, and puzzles to keep them entertained and physically and mentally active.
  • Use preventative medication to keep fleas, ticks, heartworms, intestinal worms, and other parasites at bay.
  • Vaccines and immunizations can be determined on a case-by-case basis by your veterinarian and the American Association of Feline Practitioners (AAFP) for healthy cats with FIV.
  • If your cat is FIV-positive, they should be the only cat in the household, unless you choose to adopt a second FIV-positive cat.
  • There is currently no cure for FIV-positive cats. The best you can do is good management of the illness by treating any secondary infections as they occur with antibiotics and keeping their quality of life high so they can continue to have longer asymptomatic periods. Pet insurance can help you manage the costs of veterinarian visits and treatments; however, FIV is listed as a pre-existing condition, meaning terms, conditions, and coverage vary depending on the provider.


The best way to avoid FIV is through prevention, and since it's spread through direct contact, you want to keep your cat away from any infected cats.

FIV can't survive outside of a cat's body in a normal outdoor environment for very long and can be easily killed with soap and water or a household bleach mixture, so make sure you wash your hands and disinfect surfaces thoroughly if you have handled an FIV-positive cat.

If you are adopting a new cat into the family and already have another cat, make sure they are tested prior to bringing them home. Many times, FIV-infected cats won't receive a diagnosis until years after they are infected. If your infected cat is part of a multi-cat household, all the cats in it should be tested. Since FIV is difficult to transmit, a household where cats get along comfortably makes it less likely for FIV to spread.

Spay and neuter your cats to prevent aggressive behavior such as biting, which is the main cause of FIV transmission. It can also reduce spread during mating and birth.

There is no vaccine currently available for FIV. While there was one available in the US and Canada, it was discontinued due to the risk of sarcoma and false positives on FIV tests.

The Bottom Line

To sum it up, understanding FIV and its impact on your cat's health is vital for responsible pet owners. By recognizing the symptoms, knowing how to get your cat tested, and taking preventive measures, you can ensure your feline companion's well-being.

If you notice any signs of FIV in your cat or suspect they may be at risk, don't hesitate to consult a veterinarian. Early detection and proper care can make a real difference in managing the virus and providing the best possible life for your cat. Whether or not your feline friend is at risk for FIV, it's important to make sure they get regular vet checkups. Look to our top pet insurance providers here.

How long do cats with FIV live?

While FIV can be dangerous, cats who receive proper care can live long and happy lives -- sometimes up to 15+ years.

What does FIV do to a cat?

Cats infected with FIV may experience behavioral changes, seizures, and other neurological conditions. Cats may also suffer from weight loss, cancer, or blood diseases.

How contagious is FIV?

FIV is only transmittable amongst cats and it quite difficult to transmit. However, you should always take precautions to protect your cat from contracting FIV.

About The Author

Bryan Huynh

Bryan Huynh

Product Tester & Writer

Bryan Huynh is a dedicated Product Tester & Writer. Just as insurance has your back, Bryan works to review and inform you about the wide range of insurance products available, ranging from business, auto, health, home, pet, to life insurance.

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