AROS Foundation | Babesiose

FelV (Feline Leukemie Virus)

Our adult cats are tested for FIV and FeLV. But what is FeLV? And what does it mean if a cat tests positive?

What is it?

Feline Leukemia Virus, abbreviated FeLV, is a virus that, like FIV, occurs worldwide in cats. FeLV even belongs to the same virus family as FIV (Retroviridae). The virus attacks the immune system of cats and can cause malignant tumors. A cat infected with the virus has about a 40% chance of overcoming it, depending on age and health. If the cat does not overcome the virus, it remains permanently infected and has a high risk of developing serious diseases that can lead to death. It is estimated that 70 to 90 percent of all persistently infected cats die within two to three years after the infection is detected.

What are the symptoms?

Because the virus weakens the cat’s immune system, the symptoms seen are the result of secondary illnesses:

Loss of appetite
Gradual weight loss
Poor coat condition
Enlarged lymph nodes (leukemia)
Persistent fever
Pale mucous membranes (gums, eyes)
Inflammation of the gums (gingivitis) and mouth (stomatitis)
Infections of the skin, bladder, and upper respiratory tract
Persistent diarrhea
Changes in behavior and possibly other neurological disorders
Eye abnormalities
In catteries, abortion of kittens and/or other birth defects

How is the infection transmitted?

Cats infected with FeLV shed the virus through bodily fluids such as saliva, nasal discharge, blood, urine, and feces. Most infections occur through fighting (another very good reason why we require neutering) and through close social contact. A mother cat can also transmit the virus to her kittens.

The virus does not survive long outside the cat’s body—probably only a few hours.

How is FeLV tested?

Testing can be done using a Snap test. However, this test can give a false positive result. If a cat tests positive with us, we will perform a more extensive blood test to confirm whether the cat is truly positive. It is not advisable to test cats under 6 months old because kittens can have antibodies and thus test positive without having the disease. Therefore, we only test adult cats unless a kitten shows suspicious symptoms.

What is the treatment?

Unfortunately, there is currently no treatment that fully eliminates a FeLV infection. Treatment focuses on maintaining a good quality of life. Efforts are made to counteract the consequences of the infection, such as a weakened immune system, anemia, and cancer.

It is important that a cat with FeLV is isolated or lives together only with other cats infected with FeLV.

There is a vaccine against FeLV, but it is not fully effective.

Example of a negative FIV / FeLV test result