Well, before i can answer your question, I need to ask you a few questions:
1. What kind is he and how much does your bunny weigh?
2. How old is he?
3. What type of pellet are you feeding him?
4. Is the Pellet timothy hay based or alfalfa, and does it have any other things in it, like nuts etc?
5. How much of the pellets do you feed him per day?
6. Does he get treats? What kind and how much per day?
7. Does he get greens? What kind and how much?
8. Do you feed him hay? If so what kind of hay? Is alfalfa part of it?
9. How much exercise does he get per day?
Okay, so I know that is alot of questions, but it will at least help me narrow down what's going on, and don't worry, I'm not here to scold anyone if in my opinion something is too much, or not the kind of food I would recommend. Just am looking to help .