Facts about FeLV:
• FeLV is a virus that damages a cat's white blood cells, affecting their immune system.
• Outdoor cats and those cats living with FeLV+ cats are at most risk from this virus.
• FeLV is a highly species-specific virus. It cannot be spread from cats to humans (or from cat to any other non-feline species).
• FeLV is easily passed between cats. An FeLV+ cat can transmit the disease to FeLV- cats through normal day-to-day activities, including grooming and sharing food bowls.
• About 3% of all U.S. cats are infected with FeLV. For cats that roam freely outdoors, the rate of infection can reach 70%.
• FeLV+ cats should be kept as healthy as you can possibly keep them. They must remain indoors, free from stress, kept on a high-quality diet, and be treated by a vet as soon as any symptoms appear.
What is the Feline Leukemia Virus (FeLV)?
FeLV is one member of the retrovirus family like Feline Immunodeficiency Virus, or FIV. The word “Leukemia” actually means cancer of white blood cells. However, there are other fatal diseases associated with FeLV. One of the most common effects of FeLV is immunosuppression in which cat’s white blood cells (part of the immune system) are infected and damaged or killed by the virus.
How common is the infection?
About 3% of all cats are infected with FeLV in the U.S. The rate of infection increases greatly (to 13%) if the cat is ill, very young, or at high risk for getting the infection. In large, multi-cat households or when cats roam freely outdoors, the rate of infection can reach 70%.
How is FeLV spread?
FeLV is shed though the cat’s saliva, nasal secretions, feces and urine, and can be transmitted through an infected mother’s milk. A high portion of cats infected with FeLV obtained the virus though cat fights. It can also be transmitted from cat to cat though the shared use of food/water bowls, litter boxes, and mutual grooming. Once a cat has been infected with FeLV, it will remain infected for the rest of its life. FeLV can survive for a few hours outside of the cat’s body under normal household circumstances. Household detergents and bleach will effectively kill the virus.
What cats are at greatest risk of infection?
Cats at greatest risk are, of course, those exposed to infected cats. These cats include those living with infected cats, cats allowed outdoors where they may be infected by an FeLV positive cat, or kittens born to infected mothers. Kittens 6 months or under are at higher risk for infection than older cats. Additionally, densely populated areas have higher numbers of infected cats than rural or less populated areas.
What are the signs of disease caused by FeLV?
There are a variety of ways FeLV can adversely affect a cat’s body. It may cause degenerative diseases, blood disorders, cancerous diseases (such as lymphosarcoma and leukemia), and suppression of the cat’s immune system, leaving the cat at risk for secondary illnesses.
In the early stages of the FeLV infection, cats commonly exhibit no sign of illness. Over time, the cat’s health may progressively deteriorate or it may acquire recurrent illnesses. Signs may include: eye conditions; loss of appetite; pale gums and other mucus membranes; weight loss; poor coat condition; persistent fever; enlarged lymph nodes; inflammation of the gums and mouth; infections of the skin, urinary bladder, and upper respiratory tract; persistent diarrhea; seizures, behavior changes, and other neurological disorders.
How can I keep my cat from becoming infected?
The only sure way to protect cats is to prevent exposure to FeLV-infected cats. If you allow your cats outside, provide supervision for them, or provide a secure enclosure to prevent your cat from leaving or other cats from getting in. House your healthy cats separately from infected cats. Do not share bowls or litter boxes between healthy and infected cats. And, although it is not 100% effective, there is a vaccine to help prevent against FeLV.
Can I protect my other cats?
There is a vaccine available, but it is only 80 to 85% effective at protecting cats from
FeLV. If your cat is an indoor cat who has no contact with FeLV positive cats, there is
no need for the vaccine. Cats who are already infected will not benefit from the vaccine.
How should FeLV-infected cats be managed?
While there is no treatment to cure FeLV,there are ways you can maintain the health of your FeLV positive cat. Prompt and effective care and management of any secondary infection that occurs in your cat is essential. You should closely monitor the health of your cat, notifying your vet of any changes. Furthermore, visit your vet at least once every six months for a complete wellness exam.
Additionally, your FeLV positive cat needs to be an indoor-only cat. This will reduce your cat’s exposure to secondary illnesses it may acquire from other cats, and will protect other cats from infection. Also, maintain good nutrition for your cat, reduce his/her stress, control parasites, and remember to provide early and aggressive treatment of any symptoms that appear.
Don’t forget to love and cherish your cat every day!
How long can I expect my FeLV infected cat to live?
It is hard to predict the life expectancy of an FeLV-positive cat. These cats can live from months to years after being diagnosed. In many cases, FeLV positive cats can lead a comfortable life through the combined efforts of the owner and veterinarian. However, 80 to 90% of infected cats die within three and a half years of being diagnosed.
Additional thoughts:
If you already have cats and decide to bring a new cat into your home, it is recommended that you test the new cat for FeLV if it has not already been tested. Too often, people unknowingly rescue FeLV positive cats, risking infection of the cats already in the household. Please test all new cats prior to making them a part of your cat family.
** Download our FeLV brochure (
PDF)
