I'm sooo sorry Sonny is not doing well. I think the best bet it to let the experts tell her. IMO you need to take him into a vet for a check-up and tell the vet all the problems. Also if you go to a different vet be sure to have all Sonny's vet records on hand. The new vet will need to see the difference in weight loss and so forth. The vet can then either verify your concerns or he can lay them to rest. If it is to verify them then your mom will hear them first hand from a vet and can really not argue the fact so you can both let him knowing you are doing what is best for him. If it is the lay your concerns to rest then all the better. Sonny can stay with you for awhile longer and you can get some advice from the vet as how to help him best gain some weight and do whatever he needs done. Good Luck and keep us posted. I will hope for the best results for Sonny in either instance.