Feline leukemia virus

Feline leukemia virus, usually shortened to FeLV, is a retrovirus that spreads between cats through close contact. Saliva, nasal secretions, mutual grooming, shared bowls and bites can all pass it on, and an infected mother can infect her kittens. The virus does not last long outside the body, so it is rarely caught from a room or from a person's hands.

Some cats clear the virus or keep it under control. Others stay infected for life, and over time may develop poor appetite, weight loss, pale gums, recurrent infections, anemia or cancers such as lymphoma. Many infected cats look well for months or years first. A vet diagnoses FeLV with a blood test, and a positive screening result is usually confirmed with a second test.

Kittens are the most vulnerable, and the vaccine is treated as one of the core vaccines for kittens. For adults, vets suggest it depending on lifestyle, such as outdoor access or a household with cats of unknown status. Testing every new cat before it meets resident cats is standard advice. If your cat tests positive, ask your vet about care, indoor living and how to protect other cats at home.