This led them to develop Blue Buffalo Dog Food, which contained only the finest natural ingredients to promote a strong immune system. Blue Buffalo dog food does not contain by-product meals, wheat, corn, or soy proteins, nor artificial flavors, colors, or preservatives. As far as I can see, none of their recipes contain dairy or egg, either. They produce two grain-free lines of dog food, a Limited Ingredient line, and an antioxidant-rich Life Protection line. All of their foods ...