Feline leukemia virus (FeLV) remains one of the most important causes of disease and death in cats. It causes a variety of malignancies, but persistent infection can also cause severe immunosuppression and profound anemia. The virus is present worldwide.
Prevention and Control: A test and removal program to rid catteries and multicat households of FeLV can be extremely effective if these guidelines are carefully followed:

1) All cats should be tested for FeLV viremia (IFA is best). 2) All viremic cats should be removed. 3) All dishes, litterpans, and bedding should be disinfected. 4) All movement of cats in and out of the cattery should be prevented. 5) All cats should be retested after 12 weeks to detect cats that may have been incubating the virus at the time of the first test. 6) The quarantine can be lifted when all cats have tested negative on two consecutive occasions, 12 weeks apart. 7) All cats should be tested and quarantined before introduction to the cattery. Ideally, two tests 12 wk apart should be done. 8) Breeding should be only to cats known to be FeLV-negative, and cats should be introduced only from FeLV-negative colonies.