I know the recommendations of no cooked/baked/smoked bones, no rawhide, no weight barring bones (which are shoulder bones weight barring?). But why are bully sticks ok? The ones I've given my chihuahuas have been quite stringy after they have chewed on them for awhile. And would seem to cause choking with an aggressive chewer. Ripley has never had one but I recently got one for her. What about rib bones? And are cows the only species to get bones from or are lamb and pig ok? Maybe it's based on the dogs size/breed?