Feline Leukemia Virus (FeLV)
This page is educational reference material for preparing questions. A licensed veterinarian examines the animal, makes the diagnosis, and sets the treatment.
Practical guide to FeLV in cats covering transmission, testing, symptoms, treatment options, prevention, and managing FeLV-positive cats.
Causes and Risk Factors
Multiple factors can contribute to the development of this condition.
- Genetic predisposition: Certain breeds are at higher risk due to inherited traits
- Age: Some conditions are more common in kittens or senior pets
- Environmental factors: Diet, toxin exposure, stress, and living conditions play a role
- Underlying health issues: Other conditions may increase susceptibility
- Immune system status: Compromised immune function can predispose to disease
Symptoms to Watch For
Early detection significantly improves treatment outcomes. Watch for these signs.
- Changes in appetite, water consumption, or weight
- Behavioral changes including lethargy, restlessness, or hiding
- Physical symptoms specific to the affected body system
- Changes in bathroom habits (frequency, appearance, straining)
- Visible discomfort, pain response to touch, or changes in posture
- Respiratory changes, coughing, or labored breathing
When to See the Vet Immediately
Diet choices should be cleared by the vet who actually manages your cat's care, especially where known conditions change what is safe or appropriate.
Diagnosis
FeLV is diagnosed with a viral antigen test. AAFP guidance starts with a point-of-care ELISA. A positive result in a healthy cat is confirmed with a second test, and a cat who may still be early in infection is retested later. Immunofluorescence or PCR is used when the screening tests disagree. A negative test on a kitten who was just exposed does not finish the question.
Treatment Options
There is no drug that clears FeLV. Care is keeping the cat indoors, separating them from uninfected cats, staying current on the care an FeLV-positive cat needs, and treating secondary infections as they appear. The veterinarian chooses those drugs and doses. The FeLV vaccine does not treat a cat who is already infected.
Prevention and Management
- Regular veterinary checkups (as recommended by the AVMA for all companion animals) for early detection (annually, or semi-annually for seniors)
- Maintain a healthy weight through proper nutrition and exercise
- Keep vaccinations and preventive medications current
- Breed-specific health screenings recommended by your veterinarian
- Provide a low-stress, enriched environment
- Follow your vet's recommendations for diet and lifestyle modifications
Cost of Treatment
Treatment costs vary based on severity and duration.
| Treatment Type | Estimated Cost Range |
|---|---|
| Initial Diagnosis | $200 – $800 |
| Medication (monthly) | $30 – $200 |
| Ongoing Management (annual) | $500 – $3,000 |
Quick Answers
Is this condition curable?
Progressive FeLV infection is not cured. AAFP retrovirus guidelines separate progressive infection, which stays antigen-positive and shortens life, from regressive infection, which can become antigen-negative and may not cause disease. A single positive screening test needs a confirmatory test before you treat the result as a life sentence. No antiviral reliably clears progressive infection. Care is prevention of secondary disease and a plan for when lymphoma or bone-marrow failure appears.
How can I afford treatment?
Do not budget FeLV as a monthly antiviral. Budget confirmatory testing now, and later bills for anemia, lymphoma, or infections if the infection is progressive. Ask what a quantitative PCR or IFA confirmation costs before you change how the cat lives. Vaccinating housemate cats and keeping the infected cat from fighting are cheaper than those later diseases. A policy started after the positive test will exclude FeLV-related care.
Editorially reviewed by the Pet Care Helper AI editorial team
Verified by Paul Paradis (editorial lead, Boston, MA) against the clinical references below. We are not a veterinary practice; see our medical review process and editorial team for the full workflow.
Cross-checked against:
- ISFM Feline Medicine Guidelines — feline-specific guidance
- Cornell Feline Health Center — client-facing feline reference
- Journal of Feline Medicine and Surgery (JFMS) — peer-reviewed feline literature
- Merck Veterinary Manual — clinical reference
Spotted an error? Email corrections@petcarehelperai.com. Published corrections are logged in our corrections log.
Feline leukemia virus spreads in saliva, through mutual grooming, shared bowls, and bites. The usual screen is an antigen test. A positive result in a healthy cat is often repeated, because some infections clear. Vaccination is a clinic conversation for a cat that goes outside or meets unfamiliar cats. An indoor cat that tests negative and stays indoors is at the low end of the risk.