I feed my dogs a grain free diet, and I supplement with raw meaty bones, fruits and vegetables. I have to be careful of what food I feed, because my girl has difficulties with high percentages of protein, and a lot of grain free food seems to have 25%+. I have to stick between 20 and 23%, or she gets very sick.
As a very special treat, I give them some uncooked spaghetti. For some reason, Sonya absolutely loves it, even more than her biscuits. It's very strange.