Pet Education

Browse our veterinary-reviewed Dog and Cat Illness Guide to learn more about pet health. Always talk to your veterinarian if you have a concern about your pet's symptoms or health.
Pet Assure allows pet owners to save on their pet's veterinary care, even pre-existing conditions. Click here to learn more.

Feline Leukemia Virus


Feline leukemia virus (FeLV) is a common viral disease in cats. It is the most common cause of cancer in cats and is usually fatal.

FeLV causes many diseases by invading and replicating inside the cells. This kills the cell or causes it to become cancerous. Some results from FeLV include:


FeLV is more common when there are multiple cats in close contact, and in stray or outdoor cats.

An infected cat can transmit the FeLV virus through prolonged moist contact. For example:



Your veterinarian will probably perform at least one of these tests:


There is no cure to eradicate FeLV from the body, but your veterinarian will treat the signs to relieve some discomfort:

To prevent other secondary diseases:


You can manage the spread of the disease in an infected cat:

To keep your cat from contracting the disease:


Typically, FeLV is fatal. However, cats that test positive for FeLV may live for months to years with good quality of life, depending on any secondary diseases.

Medically Reviewed by Sara Ochoa, DVM

Welcome Veterinarians

Pet Assure is the largest veterinary network in the U.S. with over 5,600 veterinarians.

Pet Assure powers DVM Network, a brand built to support our participating veterinary professionals and help them grow their practice.

Visit to learn more.