Should You Skip Your Cat’s Yearly FeLV Vaccine?
Deciding whether to vaccinate your cat annually can be challenging, particularly with diseases like the Feline leukemia virus (FeLV). As an infectious virus affecting only cats, FeLV is one of the leading causes of illness and death in felines. Understanding the risks, transmission methods, and benefits of vaccination is crucial in making the best decision for your pet’s health.
What Is Feline Leukemia Virus (FeLV)?
FeLV is a virus that attacks a cat’s immune system, leaving them vulnerable to a range of secondary infections, anemia, and cancers such as lymphoma. It is globally prevalent and primarily spreads through:
- Saliva exchange during grooming or biting
- Sharing feeding bowls or litter boxes
- From mother to kitten via placenta or nursing
Extended close contact is often required for transmission. Although incurable once established in a cat’s bone marrow, some cats can clear the virus if detected early. Sadly, for persistently infected cats, the average survival time is less than three years.
Clinical Signs of FeLV
- Pale gums indicating anemia
- Decreased appetite and weight loss
- Poor coat condition and gingivitis
- Fever and enlarged lymph nodes
- Chronic diarrhea
- Recurring skin, respiratory, and urinary infections
As the immune system declines, the symptoms intensify, often culminating in life-threatening complications and cancers.
Importance of Vaccinating Against FeLV
Vaccination is the most effective way to prevent FeLV, especially in kittens and outdoor cats. Kittens should begin the vaccine series at 8 to 12 weeks of age, followed by a booster 3 to 4 weeks later. Adults that live outdoors, in multi-cat environments, or in contact with unknown-status cats also require annual vaccinations.
In contrast, strictly indoor adult cats who do not come into contact with other cats may not need annual boosters after the initial series. In these cases, FeLV vaccination is considered non-core.
Effectiveness and Safety of FeLV Vaccines
Modern FeLV vaccines offer over 85% protection from persistent infections. Some utilize advanced RNA-particle technologies that ensure protection lasting at least two years. Studies affirm these vaccines significantly reduce disease incidence and severity.
Like all vaccines, FeLV shots carry minimal risks, most commonly:
- Mild soreness at the injection site
- Fever or lethargy
Rarely, injection-site sarcomas (a type of tumor) may develop, but the overall incidence is very low. Veterinary practitioners carefully assess risk versus benefit when advising on annual vaccines.
The Role of Testing
Testing before vaccination is highly recommended, particularly when a cat’s FeLV status is unknown. ELISA tests detect the virus in the bloodstream, even before symptoms emerge. Cats already infected with FeLV derive no benefit from vaccination.
Who Should Be Vaccinated Annually?
Annual boosters are advised for:
- Outdoor cats
- Indoor/outdoor cats
- Cats living with others of unknown status
- Multiple-cat households
- Cats previously vaccinated due for a booster
For indoor-only cats with no potential exposure, your veterinarian may recommend pausing yearly vaccines following the initial series, provided lifestyle risks remain low.
Decline in FeLV Over Time — But Risks Remain
Thanks to widespread vaccination, early testing, and a shift toward indoor living, FeLV incidence has dropped. However, in environments where cats have outdoor access or interact with strays, FeLV continues to pose a real threat.
Conclusion
Skipping your cat's yearly FeLV vaccine should never be a casual decision. Discuss your cat’s lifestyle and exposure risk with your veterinarian. For at-risk cats, annual vaccination is a critical preventive measure. For indoor-only cats, tailored veterinary guidance ensures balanced protection without unnecessary treatments.
