We have a black/tan dobie. When she was a pup, I had her on Solid Gold food for puppies. When she got older, I began to feed her the adult food. It gave her dandruff, and itchy skin. I then switched her to other foods, which gave her the most nasty egg farts, lol. It's bad when the dog stinks up the bedroom, and not your husband, haha.
I put her on Iams large breed food, and her coat is perfect. She doesn't itch, has a shiney coat, and no gas (yeehaw). So, my point is, when finding the right food for your dog, keep an eye on the skin, coat, and definetely gas (irritating tummy).