My 4 year old Mini Rex buck is losing weight. He's always been a little chunky, since he was a baby. I free fed him when he was young, but because he got so fat, I started putting him on rations. I noticed recently that he was looking a little skinny, so I started giving him a bit extra, in hoped that would bring him back to normal size. But he's still slowly losing weight. He's had no change in attitude or general health, other than that. The only recent change I've made in diet is switching to a different feed. I had them on a 12% all stock for a long time. They all did great on it, but when the buck started losing weight, I just went ahead and switched him over to a real rabbit food. I think it's a 16% protein ration. What do I do? Should I try worming him? Is there any special supplement that I should give him? I really appreciate any suggestions! I'm getting worried about him...he's one of my first rabbits...kind of my baby.