How long does it take for raw bones to spoil?

I feed my dog raw meaty bones pretty frequently. I just god a largish deer bone from a friend, the dog ate all the meat within a few hours and now only the clean bone is left. She's been chewing on it for a few days now, and it will probably take her forever to finish it. My question is, do meatless bones go bad- and how long would that take?

No they don't go bad if they are purely bone and all the meat has gone, however, you should throw away all the weight bearing bones anyway, so if it is a big weight bearing leg bone then throw it next time she leaves it alone.

It can go bad to the point where it makes the dog sick - and the dog will keep eating it anyway. Their stomachs can take that kind of punishment. Dogs will take up bones that have been buried for months a chew ate them with no permanent effects. Raw meat starts to 'spoil' the very instant that the animal dies. The degree and rate of spoilage is determined by time, environment, exposure and the types of bacteria attacking it. Meatless bones are still full of marrow until the dog cracks the bone and eats that too. Farmer up the road cut up a roadkill deer a few months ago and tossed a leg to his dog. The dog still chews on it occasionally. My own dog has a beef hip bone that he has been burying and retrieving for over a month now.