We have a 16 week old German Shepherd male. Is it normal for him to have such a sensitive belly. We got him when he was 7 weeks old and he has had 3 bouts of diarrhea. Our vetenarian told us that GSD have sensitive GI's. We have not changed his food or treats. We buy him the Purina Pro Plan Puppy formaula, which from what i have gathered is good food. We give him milk bones or treats we buy from bulk at Tops Market. The treats we buy in bulk are made somewhat locally and in the USA. I was just wondering if anyone had any suggestions or tricks to try?