FeLV is one of the most serious infectious diseases in cats, causing immune suppression, anemia, and increased lymphoma risk. Vaccination is available and highly effective — prevention is far better than treatment.
The immune system is under chronic attack. Energy levels decline progressively, and the cat may spend most of the day sleeping.
Poor nutrient absorption and systemic inflammation lead to gradual muscle wasting despite eating.
Immune suppression leaves the cat vulnerable to bacteria, fungi, and secondary viruses that a healthy cat would fight off easily.
FeLV destroys red blood cells, causing anemia. Gums that are white, pale pink, or yellow signal a serious problem.
Enlarged nodes in the neck, armpits, or groin may indicate lymphoma — the most common FeLV-related cancer.
Nausea, mouth sores, and systemic illness combine to reduce appetite significantly in FeLV-positive cats.
FeLV is transmitted primarily through close contact — grooming, shared food bowls, and bite wounds. Kittens and young cats are most susceptible. The virus spreads through saliva, nasal secretions, urine, feces, and milk, making it especially common in multi-cat households and catteries.
After exposure, there are three possible outcomes: transient infection (the immune system clears the virus within 16 weeks — most common in adults), latent infection (virus lies dormant in bone marrow but may reactivate under stress), and persistent infection (virus replicates continuously, causing ongoing immune suppression — most serious outcome). Persistent FeLV-positive cats have a median survival of 2–3 years.
Vaccination against FeLV is strongly recommended for all cats with outdoor access or contact with unknown cats. The vaccine does not treat existing infection, so testing before vaccination is important. Regular screening at annual checkups allows early detection of any health changes.
CatsMe helps you monitor your FeLV-positive cat's weight, appetite, and energy level — the three most important daily indicators. Building a consistent record means any early decline is caught before it becomes a crisis.
Get Started FreeMany FeLV-positive cats live comfortably for years with proper care — kept indoors, minimizing stress and secondary infections, with regular vet monitoring. Quality of life depends heavily on whether the cat develops lymphoma or severe anemia.
Primarily through prolonged close contact — mutual grooming, shared food and water bowls. Casual contact (sharing a room) poses low risk. The virus does not survive long outside the body and cannot infect humans.
Vaccination is generally recommended for cats under 1 year old and any cat with outdoor access or exposure to other cats. For strictly indoor adults with no contact risk, your vet may advise that the benefit is lower — discuss the specific situation.