Diamond Naturals Grain-Free Chicken & Sweet Potato Formula Dry Dog Food, 28-lb bag; Though dogs have adapted to a domesticated, omnivorous diet over the centuries, a protein-based diet free of grains more closely mimics their ancestral beginnings. Dogs are able to digest grains, but the bodies don't break down grains as efficiently as they do proteins and fats. A chicken protein, grain-free formula for all life stages with sweet potatoes provides highly digestible energy and limits exposure to allergy triggers for your sensitive dog. The first ingredient is real chicken for superior taste and nutrition. Supplemented with fruits and vegetables, this Diamond Naturals Grain-Free Chicken & Sweet Potato Formula provides natural antioxidants for optimal health and vitality.