Natural Balance® L.I.D. Limited Ingredient Diets® Potato & Duck Formula is a proven formula for dogs with allergies based on our unique protein and carbohydrate blend. Some dogs may be highly sensitive to commonly used proteins, carbohydrates and food additives in their diet. Allergic reactions can lead to irritable bowel, upset stomach, and a number of skin problems. Natural Balance® has created Potato and Duck formula for dogs with these food allergies. Our Potato and Duck formula combines fresh duck, a source of animal protein that most dogs have not been exposed to, and a source of carbohydrate not commonly found in dog foods, along with effective natural ingredients to help rebuild the dog's immune system.