The best authority on this is the Whole Dog Journal. I've posted this several times. They analyze all the ingredients to create their list of acceptable foods, and they have pretty high standards. February is when they always do their dry food, so check it out next month. They have a 14 day FREE trial! They stress that you CANNOT rank the foods. They are either good or not. Every dog is different. Loki does better on Canidae then on Natural Balance, though both are on the list. Another dog may do better on Natural Balance. As long as the food you choose is on this list, you can be sure you are feeding quality food. The only other way to know is to simply READ THE INGREDIENTS.
www.whole-dog-journal.com