If you're a cat parent, you may have heard of FIV, but what is it? FIV is short for feline immunodeficiency virus, which is an infectious retroviral disease in cats. FIV is a lot like HIV in humans: It attacks a cat's immune system, weakening it over time and leaving them vulnerable to secondary infections. Once a cat is infected with FIV, they're infected for life.

Keep reading to learn more about FIV, including its signs, how to prevent the virus in your cat and how FIV treatment works.

Signs of FIV

FIV is a slow attacking virus; it can take years for signs to appear. Furthermore, an FIV-infected cat may get sick and then get progressively worse or may only show signs of the virus sporadically.

When signs of FIV do appear, they're due to secondary infections. Because FIV weakens a cat's immune system, they become susceptible to other illnesses.

Signs vary widely and may include:

  • Enlarged lymph nodes
  • Fever
  • Loss of appetite and weight loss
  • Unkempt hair or coat
  • Vomiting or diarrhea
  • Sneezing or runny, swollen eyes
  • Non-healing wounds
  • Severe gum inflammation
  • Skin redness or sores
  • Abnormal litter box behavior, such as frequent urination, straining, urinating outside the box and/or bloody urine

Gray cat asleep on white rug.

A cat that's infected with FIV can only pass on the virus to other cats — not to humans or other animals. It usually spreads via bite wounds. FIV can also be transmitted in utero to kittens through their mother's placenta.

Diagnosing FIV

Based on historical data, FIV-positive cats are most likely an outdoor, male cat that fights or has bite wounds. They're typically feral, stray and not neutered.

FIV is diagnosed through a quick blood test. Make sure to have a cat tested for FIV before bringing them into your household. Also, keep in mind that kittens younger than 6 months who test positive may not actually be infected. These kittens should be isolated from other cats and tested again once maternal antibodies clear from their system; this usually occurs at around 6 to 7 months of age.

No test is 100% accurate, so consult with your veterinarian to determine whether your cat needs additional testing.

What Is FIV Prevention?

There was an FIV vaccine available until 2017, but it was discontinued for multiple reasons. The easiest way to prevent FIV in your cat is to keep them inside and away from cats that could infect them. If you choose to let your cat outside, keep them on a leash or in an outdoor enclosure (like a cat patio).

What Is FIV Treatment?

While there's no cure for FIV, FIV-positive cats can live a long, good-quality life if they're well cared for and regularly see a vet for preventive care. If you have an FIV-positive cat, you should take them to the vet for a checkup every six months.

Treatment for clinical FIV is centered around controlling or treating secondary infections, keeping the cat indoors to prevent the spread of the disease and extending the period of time that the cat is asymptomatic. FIV-positive cats should be spayed or neutered.

For FIV-positive cats that don't show signs of the disease, treatment consists of feeding high-quality, complete and balanced nutrition, good parasite control, preventing secondary infections, dental care, appropriate mental and emotional enrichment for stress reduction and monitoring for signs of the disease.

Living With an FIV-Positive Cat

Since FIV-positive cats' immune systems are compromised, pet parents should be extra vigilant. Avoid feeding an FIV-positive cat raw food because of the risk of salmonella (or the veterinary term for salmonella in cats: salmonellosis). A cat with a compromised immune system is at a higher risk of contracting salmonellosis and potentially may have more severe symptoms. Also know that even a slight respiratory infection could result in life-threatening pneumonia. Due to the risk of infection to other cats, it has been recommended that FIV-positive cats live in households either without other cats or with cats that are all FIV-positive. However, healthy cats and FIV-positive cats can co-exist in the same household if they get along and do not fight.

With proper attention and care, FIV-positive cats can lead healthy, happy lives and make wonderful companions for years to come.

Dr. Sarah Wooten Dr. Sarah Wooten

Dr. Sarah Wooten graduated from UC Davis School of Veterinary Medicine in 2002. A member of the American Society of Veterinary Journalists, Dr. Wooten divides her professional time between small animal practice in Greeley, Colorado, public speaking on associate issues, leadership, and client communication, and writing. She enjoys camping with her family, skiing, SCUBA, and participating in triathlons.

Related articles

Why Do Cats Stick Their Tongue Out?

They look super cute when doing it, but why do cats stick their tongue out? Read on to find out what it means!

How to Care for an Injured Cat

Cat injuries require special attention—earn how to recognize a cat injury, details about cat wound care and recommendations for helping cats heal at home.

Is Your Cat Scooting on the Carpet? Anal Glands May Be the Culprit

Find out why a cat scooting on carpet could be a sign of inflamed anal glands and what you can do to help relieve your cat's agitation.

Deciding if a Natural Food is Best for Your Cat

Understand what natural cat food really means and how to pick a high quality natural cat food for your furry friend.

Cat Parents: Bringing Your New Cat Home

Discover ten ways to care for your new cat after adoption, from preparing your home before she arrives to making her feel comfortable once she's arrived.

Do Cats Fart?

While it may not be common, cats to indeed pass gas. Learn how your cat's food impacts their gassiness and whether you need to be concerned.

Cat Kidney Health: What You Need to Know

Cat obesity is a significant problem - learn more about helping your cat become trimmer and healthier through improved nutrition.

Why Does My Cat Keep Unrolling Toilet Paper?

Cats and toilet paper are a mischief-making combo. Learn why your cat is so fascinated with unrolling toilet paper (and how you can help them stop).

Are Cats Protective of Their Humans?

Dogs are well-known for their loyalty, but are cats protective too? Learn whether cats defend their people and how to deal with an overprotective kitty.

Special Care Considerations for Senior Cats

Senior Cats & Their Special Care Needs

Why Do Cats Bite While Playing?

Learn what's behind your cat's playful biting, whether it's a cause for concern, and how to curtail it if they get a little too rough.

Keeping Your Cat's Mouth Healthy

Learn how to brush your cat's teeth vs. having a professional cleaning done, as well as common signs that she might have an oral health problem.

What You Should Know About Cat Sneezing

Like human sneezing, cat sneezing is normal to a certain extent, but it can signal an underlying health concern that requires support or treatment.

Why Do Cats Meow?

Learn what your cat's meow really means, so you can understand what they are trying to communicate to you.

Your Cat's First Month At Home: Tips & Suggestions

Learn more about the basics of cat care in the first month, including choosing the right cat bedding, cat toys, cat carriers, pet id tags and litter boxes.

Cat Heart Health and Feline Heart Disease

Learn more about the causes of feline heart disease and the signs you can watch out for to promote heart health in your cat.

Stomatitis in Cats: Causes, Diagnosis & Treatment

Learn about stomatitis in cats, an inflammation of the mouth, including the two types, symptoms of the condition, and treatments your vet might recommend.

Feline Idiopathic Cystitis: Symptoms, Diagnosis & Treatment

Learn about feline idiopathic cystitis (FIC), which causes lower urinary tract problems in cats, including risk factors, symptoms & treatment options.

How to Put On a Cat Harness

Discover which harness style is best for your feline friend and learn how to put on a cat harness. Take your kitty for a stroll knowing they're secure.

All About Your Cat's Sleeping Habits

Learn all about your cat's sleep schedule, why she seems to be most active during twilight hours and what it means to be a crepuscular kitty.