Feline Leukemia and Feline Immunodeficiency are two diseases caused by viruses that cats can be born with or can contract, via intimate contact with another infected cat, at any time after birth. Testing for feline leukemia virus is recommended, regardless of age, for any new cat in a household. Testing for feline immunodeficiency virus is recommended for all cats over six months of age when introduced into a household. Because both diseases can lay dormant for years before causing medical problems, testing for both viruses is commonly recommended in any sick cat, regardless of any previous testing.
Knowing a cat’s feline leukemia and feline immunodeficiency virus status can help us make recommendations regarding health management for your cat. Neither virus is curable. Both can cause various clinical signs, most commonly anemia or inability to fight off even simple infections due to compromise of the immune system.
Vaccination against feline leukemia virus helps cats that are subsequently exposed fight off the infection. It can protect already infected cats against some cancers commonly associated with the virus. Our hospital recommends that all cats live strictly indoors to avoid the many dangers of outdoor living. But for those owners who decide to let their cats out, we strongly recommend vaccination against feline leukemia.
For strictly indoor cats, we consider the vaccine optional. Owners of “indoor” cats that occasionally escape or that owners let out “in my yard only” should realize that they, in fact, have an indoor/outdoor cat that could be exposed to all outside dangers. These owners should consider the vaccination. Cats are quite capable of leaving yards and returning completely unobserved by owners. If they go out at all, they are NOT indoor cats.
The vaccine for feline immunodeficiency virus is new. Vaccination can interfere with subsequent testing should the cat become ill. The Vaccine Is Not 100% Effective. As we gain more experience with this new product, vaccine recommendations may change, but, for now, we do not recommend routine vaccination against feline immunodeficiency virus.