Feline Leukemia Virus or FeLV


FeLV (feline leukemia virus) is a contagious virus that cats can spread to each other through nasal secretions or salvia. It is transmitted by mating, fighting that has biting, from the mother, and sometimes eating and drinking out of the same bowl, or sharing a litter box. The virus does not stay outside the body for long, sharing bowls and a litter box are not as likely for cats to contract the virus, but it is still possible.

New Cat in Your Home

Anytime a new cat is coming into your house, and you already have a cat(s), the new cat should be tested for FeLV and FIV (feline immunodeficiency virus). That way if the other cat does have either disease, you know not to bring the new cat into your house. If you only have one cat and your cat has never been tested it is a good idea to make sure your cat will not give anything to the new cat either.

Attacks the Immune System

FeLV is a virus that attacks the immune system. This makes it if the cat gets a bacterial, fungal, or viral infection it will be much harder for a FeLV-positive cat to able to overcome any type of infection. For cats that have FeLV and/or FIV, it is important to keep their immune system strong and make sure if the cat does get something it will be able to fight it off.

Symptoms of FeLV

Symptoms that a cat may have FeLV include loss of appetite, weight loss, enlarged lymph nodes, fever, pale gums (due to anemia or low red blood cells), inflammation of the mouth (find out more about this in the Cat Mouths article), diarrhea, seizures, neurological changes, eye problems, and abortion.

Cats can show no signs of having the infection until they get sick and can have it for many years without even knowing it. This is why when you get a cat or kitten it is important to get them tested for FeLV and FIV. It takes at least 30 days from being infected with FeLV to be able to detect it on a test and up to 60 days with FIV. If your cat has been in a fight, wait 60 days and have them tested for FeLV and FIV.


The test for FeLV and FIV can be performed at your veterinary clinic or hospital. Most veterinary clinics have these tests that can be run in-house like a pregnancy test. There are tests that test just FeLV but if your cat has been in a fight or has never been tested having the combination test is better that tests for FeLV and FIV. If you are having other blood work sent out to the lab they can also add on FeLV and/or FIV tests. These tests detect if there are antibodies in the system from the viruses. 

Kittens and FeLV

Kittens that get FeLV normally do not live past the age of three. If a young kitten gets FeLV it is likely not to live past the age of one. This is why it is important to get kittens tested and keep them away from known FeLV-positive cats.

Fight Off FeLV

Cats that have been infected with FeLV might be able to fight off the virus. It does not always happen, but if you have a healthy cat and help boost its immune system the cat might be able to fight it off. Try this product from Pet Wellbeing to help boost the immune system if your cat needs some extra immune support or if it has been diagnosed with FeLV or FIV to help keep its immune system healthy. (


If you have a cat that does go in and out of the house and there are other cats in the area, it is a good idea to have your cat vaccinated against FeLV since there is no cure and your cat can have a shortened life due to the virus, so prevention is best. Talk to your veterinarian about the vaccine and if it would be good for your cat to be vaccinated against FeLV.

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