We've been giving ours rib bones for a while and never had a problem

I don't think they're particularly prone to choking on the bones, and the major concern, like Scout said, is germs. We always make sure ours have them for long enough to get to the marrow, as that's the part they seem to really enjoy. We had some beef rib bones that didn't go over as well, cause the bone around the marrow was too thick. Pork rib bones seem to work best.