Just to go along with the chipped tooth thing from beef bones, Tango chipped her tooth pretty badly a few weeks ago after chewing on one (full of meat) for about 10-15 mins. She's a really hard chewer though, and none of our other current or past dogs ever had this happen to them though I'm not sure why. But anyway, here's a pic of her tooth now ( it's quite a bit shorter than her other one)...it doesn't seem to cause her any pain and if it does, she isn't showing it. It did turn a yellowy colour [it was very white before] though and she might have to get it pulled: