What good-looking, loved-looking dogs you have there! Hmm, maybe a certain Dingo is eating the leashes and collars when you're not looking? My friends have a shepherd mix that I sometimes dogsit for, and all leashes must be stored where he cannot get at them, or he just idly chews them to bits! He doesn't dislike the leash, or have any lack of good chew toys (as he's also helping raise two human kids, plenty of other things chewable are around), he just like to munch them!