Pet n Shape Natural Beef Lung Strips for dogs are 100% natural and contain just one ingredient, Beef Lung. Beef Lung can be helpful for dogs with a sensitive stomach, any digestion issues and overweight dogs. These treats are U.S. lab tested for safety and contain no artificial additives, colors, or preservatives. They are also free of any wheat, corn, and soy. Proudly made in the USA, these treats make a great snack for puppies, seniors or any size pup.