Feline leukemia virus is a retrovirus that infects cats. FeLV can be transmitted from infected cats when the transfer of saliva or nasal secretions is involved.
ABCD cats & vets: GUIDELINE for Feline Leukaemia Virus Infection.
Feline leukemia virus (FeLV) is one of the most common and important infectious diseases in cats, affecting between 2-3% of all cats in the United States and Canada. Infection rates are significantly higher (up to 30%) in cats that are ill or otherwise at high risk (see below).

Diagnosing Feline Leukemia Virus in Cats. Cat having a blood test at the vet.Life Expectancy of Cats with Feline Leukemia. In scientific studies, cats tend to live two to three years after diagnosis of FeLV. However, the age at which cats are diagnosed with FeLV is highly variable.
Feline leukemia virus (FeLV) is one of the most common infectious causes of disease of cats globally. Infection with FeLV can cause a variety of clinical signs, impacting a cat's longevity and quality of life.

Burmese cat with a blue collar. Feline Leukemia Symptoms. Cats in the early stages often dont show any signs of the virus.Siamese cat with a blue collar. Diagnosis. There are two blood tests for FeLV. The first is called ELISA, which can often be done in your veterinarians office.
Senior Cat Care.Diagnosis of feline leukemia is done through a series of blood work and, in some cases, a urine analysis or bone marrow analysis. If your cat is diagnosed with any type of feline leukemia, the good news is that there are treatment options available.
Senior Pet. Arthritis in Cats.Feline leukemia virus is a common disease that affects about 2% of cats in the United States. It is spread cat-to-cat and leads to the destruction of the cats white blood cells and immune system.