Feline Leukemia Virus

Last updated: August 02, 2016

Feline Leukemia virus (FeLv) is a retrovirus group that also contains Feline immune deficiency virus (FIV). Both viruses occur globally. While the virus is not transmittable to any other species, Feline Leukemia virus creates a multitude of health issues for the cat. FeLv in cats accounts for more disease-related deaths and clinical issues than any other infectious agent. The virus is associated with cancerous leukemia and immune suppression, making sick cats susceptible to diseases they encounter. While the prognosis is generally good, death often results from a combination of issues brought on by immune suppression and anemia.

FeLV Positive Cats and How to Test for Feline Leukemia

A counter top lab test done with blood from a kitten or adopted adult cat can detect FeLv within minutes. A bite from an infected animal usually spreads the virus, which otherwise survives mere minutes outside its host. This disease is not transmittable to humans, dogs, or other animals.

In multiple cat household, once FeLv cat is diagnosed, all cats should be tested to check their immune status and then vaccinated to avoid infection. If possible, house positive cats away from negative cats. Members of an established cat colony usually fight little, so a stable home life should minimize the spread of FeLv through bites. Do not introduce new cats to the household during a FeLv outbreak, as cats who feel threatened are more prone to bite and therefore transmit the disease. Though FeLv positive cats may have a decreased response to vaccines, they will respond and should be vaccinated. Preventing common respiratory problems helps keep them healthy.

How to Treat Feline Leukemia

There is no cure for FeLv; however, understanding these cats' vulnerability to infection and the importance of early treatment helps extend their lives. FeLv positive cats respond just as well as leukemia negative cats to appropriate antibiotic therapy.

If positive cats undergo surgery or dental cleaning, they should be on an antibiotic before and after the procedure. With proper antibiotic support, routine surgery or dental cleaning can be done without issue. If a cat shows signs of FeLv disease or neurologic disease, therapy includes antiviral drugs. The drug Azithromycin commonly treats FeLv issues, and other antiviral drugs have been helpful. Your veterinarian will select medications to control the specific clinical issues your cat faces.

Feline Leukemia Prevention

Indoor/outdoor cats should be tested and vaccinated to prevent respiratory viruses and FeLv. Kittens are usually given two injections at eight and 12 weeks and boosted yearly (or, after the one year booster, every two years) with the Nobivac FeLv vaccine The vaccine should prevent infection, but keeping your cat indoors provides extra insurance against cat bites and FeLv.

Caring for FeLv Positive Cat

With proper antibiotic and cautionary support, the Feline Leukemia Virus is not necessarily a death sentence. Positive cats should be kept inside to prevent virus spread to other cats. Inside cats are stable, and their quality of life remains high.

Despite the likelihood of a positive outcome, vaccinating your kittens and cats against FeLv removes the problem. Make sure your animals are up-to-date on all their vaccinations, including Feline Leukemia Virus, especially if they are indoor and outdoor pets! Insurance against disease with vaccine protection will save you the emotional stress of a FeLv-positive cat.

If you need help with cat leukemia, call us at 800.786.4751.

-Dr. Bramlage
Donald Bramlage, Doctor of Veterinary Medicine, Former Director of Veterinary Services at Revival Animal Health

Donald Bramlage, Doctor of Veterinary Medicine, practiced veterinary medicine for 30+ years and is known for his work in managing parvovirus. He received his Doctor of Veterinary Medicine from Kansas State University in 1985. He served as Revival's Director of Veterinary Services from 2011 until his retirement in 2019.