I have a new Lab puppy. He is 9 month old and has been in training for the last 2 1/2 months. The trainer is feeding him 5 cups of food a day, but the dog is not putting any weight on. I am concern and so is the trainer. We worm the dog 3 times when he was a puppy. Could there be something I need to have the dog check for? The dog food he is eating is Diamond Brand. The trainer said he was going to start feeding the dog canned pumpkin. Thanks for the help.