Feline leukaemia virus (FeLV)
Also known as Feline leukaemia, FeLV.
A retrovirus spread mainly through saliva which, in cats with progressive infection, causes anaemia, immunosuppression and lymphoma. There is no cure, but testing and vaccination prevent it.
- System
- Infectious diseases
- Is it urgent?
- Not usually
- Spreads to other cats
- Yes
- Spreads to people
- No
- Typical cost in Spain
- FeLV/FIV test, €30–55; PCR, €50–100; vaccine, €35–60 per dose.
Spread between cats through close contact. It does not affect people or dogs.
Symptoms
- In some cases, many years without signs
- Infections that keep coming back or will not clear
- Pale gums from anaemia
- Weight loss and poor appetite
- Swollen lymph nodes
- Lymphoma
Causes
The FeLV virus, which passes through mutual grooming, shared bowls and litter trays, bites and from mother to kittens. Infection can be progressive, regressive or abortive.
How it is diagnosed
A rapid blood test confirmed by PCR, because a single positive result may not be conclusive.
Treatment
No treatment eliminates the virus. Complications are treated and the cat is cared for with more frequent check-ups.
No doses, on purpose: any medicine must be prescribed by your vet for your cat.
Prognosis
Variable. With progressive infection, many cats live only a few years; with regressive infection, life can be almost normal.
Prevention
Test every new cat before it meets the others. Vaccination is recommended for kittens and for cats that go outside or live with positive cats.
Frequently asked questions
Is feline leukaemia virus (FeLV) contagious?
To other cats: yes. To people: no. Spread between cats through close contact. It does not affect people or dogs.
Can feline leukaemia virus (FeLV) be cured?
Variable. With progressive infection, many cats live only a few years; with regressive infection, life can be almost normal. No treatment eliminates the virus. Complications are treated and the cat is cared for with more frequent check-ups.
How much does it cost to treat feline leukaemia virus (FeLV)?
As a guide for Spain in 2026: FeLV/FIV test, €30–55; PCR, €50–100; vaccine, €35–60 per dose. Prices vary a lot between clinics and cities, and out-of-hours emergencies cost more.
How can feline leukaemia virus (FeLV) be prevented?
Test every new cat before it meets the others. Vaccination is recommended for kittens and for cats that go outside or live with positive cats.
More in infectious diseases
Educational content from Michipedia. It does not replace diagnosis or treatment by a vet: if you have any doubt about your cat's health, ask. Costs are a guide for Spain in 2026.