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.

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