I have a 4 month old German Shepherd and his previous vet told us that Blue Buffalo tends to cause diarrhea, he suggested Wellness, but his new vet says that Blue Buffalo is just fine. He was put on canned food for awhile to stop the diarrhea and the only thing he eats is Blue Buffalo, no treats or anything and he is still not solid. Is this being caused by the food? Would you suggest a new brand that is good for puppies?