my guinea pig has lost a lot of weight in the past weight, about a pound. We went to the vet and she said that he's very healthy but his teeth are much too long. So we got them trimmed. But he still will not eat and continues to lose weight, he is now about half the weight of his sister. Please help because I am very scarred and the vet said there is nothing I can do. I tried canned pumpkin (100% pumkin) tomatoes (his favorite) spinach, spices, timothy hay, alfalfa, grapes, oranges, bananas, and all his other normal food. but no luck he just won't eat. please respond asap!