The best prevention - keep your cat indoors at all times. Like other FIV and FIP, this condition makes cats more suseptible to infections because it depresses the immune system. FeLV can be transmitted easily through body fluids, feces, and even milk. Sharing food bowls and biting are common infection methods. Cats can also be carriers without being infected themselves.
Many infected cats do recover with treatment.
Without treatment, survival can be low. There is no cure at this time, but there are drugs that can extend a patient's life and reduce any pain. The good news is that there is a vaccine. It is spread by direct contact of saliva, blood, vomit, urine and feces. It can become airborne or it can contaminate food and water bowls, and litterboxes.