My DD just bought a house where all of the round door handles are "chewed up" by a big dog - the handles inside of a room and out side of a room. Either the dog wanted in a room or out of a room. So, her DH went to Lowe's and bought a case of the newer door handles - the flat, horizontal ones. They do not have any animals, but were warned that the newer, flat door handles are easy for a dog or cat to open. LOL