Cats - FeLV (Feline Leukemia)

Cornell University College of Veterinary Medicine article

Feeding tips:

Good quality wet food is important.  Probiotics and lysine supplements are recommended and if possible feed high iron items. I puree liver and add egg, then freeze in ice cube trays so I can thaw one or two out several times a week for them.  Feeding ground turkey and a little ground beef helps too.  If you can, give a vitamin B-12 shot once a week.


Watch for stomatitis, it is a dental issue that FeLV cats can be prone to. It can be very serious.

 More info can be found at:  https://www.petmd.com/cat/conditions/mouth/c_ct_stomatitis


Herpesvirus is common in FeLV positive cats. it will cause watery, goopy, sore eyes and respiratory infections. Vets offer drops, creams, and antibiotics;  but for some the only answer is an anti-viral like famciclovir. 

More info can be found at: https://vcahospitals.com/know-your-pet/feline-herpesvirus-infection-or-feline-viral-rhinotracheitis


Good food, a stress free environment and getting lab work (blood tests) done at least once a year to monitor the cats health are best practices for FeLV positive cats.


FeLV Vaccine:

For cats that are NOT FELV positive it is recommended that they be vaccinated against the Feline Leukemia virus especially if they will potentially be exposed to other cats. If your cat is an inside cat that does not go outdoors vaccination against FELV is not imperative. However before adopting another cat be sure to have it tested for FELV prior to exposing it to your existing cat family.

More info can be found at: https://vcahospitals.com/know-your-pet/feline-leukemia-virus-vaccination


Frequently Asked Questions:

1. What is Feline Leukemia (FeLV)?

FeLV is a virus that weakens a cat’s immune system. It is not a cancer like leukemia is in humans. FeLV makes a cat more susceptible to upper respiratory tract and other infections that tend to shorten their lifespan. FeLV is usually discovered during a routine blood test at the vet clinic, and unfortunately, these tests have a very high rate of false positives, meaning cats may test positive when they are not actually infected with the virus.

2. Is there a cure for FeLV?

Unfortunately, there is no cure; however, if the cat receives routine medical care at a veterinary clinic and is closely monitored or observed for any health changes, it can live a long, healthy life.

3. Is FeLV contagious and how is it transmitted?

FeLV is contagious and is transmitted through a cat’s bodily fluids, usually saliva or blood, but sometimes urine and feces. The virus does not live long outside of the cat’s body, so most cats contract it from direct contact with an infected cat. FeLV is not transmittable to humans or other animals. One effective way to reduce the occurrence of FeLV is through spaying and neutering because un-neutered and un-spayed cats are generally more aggressive and more prone to direct contact with other cats, thus increasing their chance of contracting the virus.

4. What are the signs and symptoms of FeLV?

Signs and symptoms of FeLV are vague and non-specific, but some might include:

5. Why are false positive FeLV tests so bad?

When a cat tests positive for FeLV, they are normally isolated from the rest of the cat population and sometimes even euthanized. After a positive test result, a cat will not be given the FeLV vaccine, meaning that even if they do not have the disease now, they could contract it later. A cat with a positive FeLV test result is stigmatized and less likely to be adopted for fear that it will infect other cats, so often these cats are taken in by a shelter/rescue, such as Emi’s Heart Rescue, that specialize in the care of FeLV positive cats. Since shelters and rescues can scarcely afford to re-test every cat they receive, an uninfected, unvaccinated cat with a positive test result could contract the virus while in the shelter. That is why Emi’s Heart Rescue has developed a specific fund set aside solely for the re-testing of cats they receive. If a cat tests negative for FeLV when retested, it is immediately vaccinated and isolated from the rest of the population, increasing its probability of being adopted into a household.

6. Is it safe to adopt a cat with FeLV?

There are several good reasons to adopt an infected cat. First, you could be saving this sweet creature from a potential death sentence since so many are euthanized. Second, if the cat is kept indoors and receives routine vet care, it can live a long, healthy life. If there are other noninfected cats in the household, they are generally safe, assuming they have received the FeLV vaccine. One of the biggest reasons FeLV cats are isolated from other cats is to reduce the infected cat’s risk of acquiring an infection since it has a weakened immune system.

7. How do I take care of a FeLV positive cat?

If you choose to adopt a FeLV positive cat, it should be kept indoors to minimize the spread of the virus and to protect your cat’s sensitive immune system. The cat should receive two wellness check-ups each year including bloodwork. You should strive to keep your cat calm and comfortable, feed them high quality food, and keep their litter boxes clean to minimize the spread of infection. It is okay to introduce another FeLV positive cat into the family, and if you adopt a FeLV negative cat just ensure they are vaccinated against FeLV for protection.