Why Feline Leukemia Vaccines Should be Taken Often

Feline Leukemia Virus (FeLV) is one of the most dangerous contagious diseases threatening cats. It is spread by contact with a cat's bodily fluids, and is passed on by cats to their offspring. It does not pass from cats to humans. It is a retrovirus which suppresses the cat's immune system bringing on a slow, drastic decline in heath which is fatal in most cases.

Feline Leukemia Virus can also cause anemia and Feline Cancer. There is no known cure. About 15 percent of cats who contract Feline Leukemia live out normal lives after treatments, but there are limited treatment options and many of them are experimental treatment modeled one new treatments for AIDs Here is some important information on vaccines available for prevention of this deadly disease:

Assess the Risk

The greatest threat from the virus is posed for cats that go outside since the way most cats become infected is through bite wounds. If you keep your cat indoors it is at low risk and after discussing it with your vet, you may decide not to vaccinate and thus avoid the risks associated with side effects from vaccination.


Your vet will test your cat for FeLV and usually also for FIV before administering the vaccine. In fact these tests are recommended any time you take a new cat into your household. If your cat has prolonged or regular interaction with any other cats outside then you should arrange for these tests as part of their regular check up program with your vet. The vet will vaccinate your cat after negative test results come back. Some forms of the test take as little as two hours to complete and others take up to two days.


The vaccine can be injected or given through a transdermal patch. The first inoculation is given to kittens at about 8 weeks old; a booster is administered within 3 to 4 to four weeks of the first dose.

Since the purpose of the vaccination is to increase your cat's immunity to FeLV by helping him create antibodies to fight the virus, there must be enough of the vaccine applied to keep the level of these antibodies in your cat's body high enough to prevent infection. This level of antibodies will decrease over time, and after 12 months there will not be enough antibodies to protect your cat from infection with Feline Leukemia. This is why your cat must receive a revaccination booster every year.

Remember that the most effective protection measure you can take is to keep your cat indoors since none of the available vaccines is 100 percent effective.