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.
Feline Leukemia Virus Quantitative Testing. Stage of infection. FeLV antigen by ELISA.Progression of disease is much more rapid in kittens, whereas some adult cats remain healthy for many years and may die of conditions unrelated to their retroviral status.

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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).

Feline Leukemia Virus (FeLV): Signs, Prevention, Prognosis.It can be spread by grooming, shared food bowls, bites, and other forms of close contact. It can also be transmitted from a mother cat to a kitten in utero and from the milk of an infected cat.

... Two other feline retroviruses, feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV), can be associated with various clinical presentations, including immunodeficiency, depending on the disease course and stage [43].
Feline Leukemia Virus (FeLV) dari Veterinary Partner.