If you are wondering what to feed or if you are feeding the proper food, read this online book. It's written by the gentleman who developed Charlie Bear Treats. It's called "See Spot Live Longer". The website is www.seespotlivelonger.com . Click on the "Articles" button. The book is on the left side of the page. It takes a bit to download but is worth it. This man did ALOT of research and presents it well in this book. The other articles are well worth reading as well.
I feed a raw diet. I make my own but I also buy Nature's Variety raw diets. They have a very good grain free kibble for dogs in 3 flavors: chicken, rabbit and duck/turkey. My Shelties are not just pets. We train and compete in a variety of venues: obedience, rally, freestyle, flyball, carting and weight pulling. They are atheletes. You don't feed atheletes junk food.