FeLVinfected

FeLV-infected refers to cats that have contracted feline leukemia virus (FeLV), a retrovirus that can cause a range of health problems in domestic cats. FeLV infects the immune system, disrupting white blood cell production and increasing susceptibility to secondary infections, cancers, and anemia.

Transmission occurs primarily through direct contact with infected saliva, blood, or nasal secretions, often via head‑to‑head or grooming interactions. Close, prolonged contact among groups of unvaccinated or immunocompromised cats heightens risk. The virus may also spread through contaminated surfaces or the environment, although this is less common. Vertical transmission from queen to kitten can occur via placenta or milk.

Early signs may be subtle, including lethargy, loss of appetite, weight loss, and mild fever. As infection progresses, cats often develop more pronounced clinical features such as persistent lymphadenopathy, nasal discharge, skin ulcers, chronic anemia, and enlarged liver or spleen. Some cats may remain clinically normal for months or years, while others succumb rapidly to AIDS‑like disease or lymphoma.

Diagnosis relies on a combination of tests. Initial screening uses ELISA or indirect fluorescent antibody assays to detect FeLV antigens in the blood. Confirmation involves PCR to identify viral RNA or reverse transcriptase activity, and flow cytometry can detect FeLV‑positive core proteins on peripheral blood cells. Bone marrow biopsies may be warranted when lymphoma or marrow failure is suspected.

Treatment focuses on supportive care; there is no cure. Management includes antibiotics for secondary infections, transfusions for anemia, and therapy for related cancers. Surgical removal of lymphomas is sometimes undertaken. Vaccination is available and recommended for kittens, stray cats, or any cat at risk of exposure, and may reduce disease severity but does not guarantee protection.

Prognosis depends on disease stage and overall health. Chronically infected cats have a median survival of several months to a few years, whereas those that develop severe anemia or opportunistic infections may die within weeks. Prompt veterinary evaluation, proper vaccination, and minimizing exposures can substantially lower FeLV transmission and improve outcomes for feline populations.