What is Feline Leukemia Virus (FeLV)

Feline Leukemia Virus (FeLV) is a retrovirus that affects cats and is one of the leading causes of illness and death among felines. It primarily attacks the immune system, making cats susceptible to various secondary infections and diseases.


FeLV is primarily transmitted through close contact between cats, primarily via saliva, nasal secretions, and urine. Common modes of transmission include:

Direct Contact: Mutual grooming, fighting, and sharing food/water bowls or litter boxes can lead to transmission.

Mother to Kittens: Pregnant cats can transmit the virus to their kittens, either in utero or through nursing.

Biting: Bite wounds can introduce the virus into the bloodstream.

Casual Contact: Although less common, the virus can spread through sneezing, coughing, and sharing contaminated bedding.


FeLV infection can lead to a variety of symptoms, and cats may not show immediate signs. Common symptoms include:


There's no cure for FeLV, but supportive care can help manage symptoms and prolong a cat's life. 

Variations and Current Understanding

FeLV has different strains that affect cats differently:

Researchers continue to study FeLV to understand its various strains, transmission mechanisms, and effects on cats' health. Vaccines are available to protect cats from FeLV, but they're not 100% effective and are usually recommended for cats at higher risk of exposure, such as outdoor cats or those living with infected cats.

It's important for cat owners to regularly test their cats for FeLV, especially if they interact with other cats, and to take preventive measures to reduce the risk of transmission, such as keeping infected and non-infected cats separate, providing a clean environment, and ensuring proper hygiene practices.