"We have two pitbulls who are "power chewers" making it very difficult to find chew toys that will last for very long. The knuckle bones last for 2-3 days (most chew toys last minutes to hours) and keep them very happy. They are so excited when they get them and chew on them day and night until they're gone. They digest them easily and they haven't had any G.I. problems at all. So far, the bones haven't left any stains on the carpet like some other chews do. Highly recommend!"