I stopped feeding my dogs Science Diet. Its OK as far as dog food goes but I found it made my two shit their brains out. I switched to a mixture of Royal Canin and Purina Pro and they go about half as much as they did. I havent check ingredients, but I believe it has more protein and less fillers.
I believe the formula for SD has changed because I didnt have issues with it in the past.
Maybe give the Purina Pro Plan puppy food a try. Both breeders I bought my dogs from swear by it and it should be readily available at most stores.
I'm so glad you're going to stick with him.
Good luck