Three days ago, I picked up my 9 week old $1500 GSD puppy from the breeder. While we were there, she told me that he had been losing fur on his tummy and she knew this was because he had an allergy to grain. She sent me home with grain-free food, instructions to supplement his diet with condensed milk, cottage cheese, and yogurt, and the puppy. He seemed okay for a few hours. That night, he began to have terrible diarrea that included mucus and blood. We took him to the vet Monday evening. The vet told us there was no way to know he had a grain allergy yet, and that all the dairy could be too much for him to handle. She diagnosed him with a yeast ear infection and coccidia, and sent me home with special shampoo for his itchiness, Hill's bland wet food, and a number of meds including Albon for the coccidia. Frustrated, I called the breeder, who told me that she "knew" the grain was the issue because of his bloodline, and that we should not have changed his diet again. So, the breeder is telling me the vet is wrong, the vet is telling me the breeder is wrong, the puppy now will not eat, drink or take his meds, and I don't know what to do. The breeder told me I could return him, but I really don't want to as I have bonded with him. I'm a first time dog owner and really don't know how to handle any of this. Any advice would be appreciated.