These drugs can be very toxic and dangerous if not given correctly, and most neighborhood vets are not qualified to give them. Blood work is a must, usually weekly to monitor their effectiveness and any side effects that might come up. Liver and Kidney function tests are also a must. This means your cat may receive 25 to 30 pills a day. The problem with this is obvious.
Most cats hate even one pill and put up quite a fight.
Also, if their stomachs are full of pills, they will probably not want to eat. Anorexia is already a problem in FeLV cats. Most researchers feel that even a single missed dose allows the virus to mutate into an even more dangerous enemy, resistant to the drugs. This does not sound very appealing to me. But I want to do whatever I can to help my cat.