what kind of cat food do you feed your cats?

i started the cats on the 3 health and they like it and eat less. i thought great, problem solved. now we found out our old man had a stone in his bladder, we had it removed last week and soon as they get the results back as to what kind it is he will probably have to have special food the rest of his life. any ideas how to keep him at his bowl and away from the other food? and how to keep the meezers away from his special food?