The subject of bones is highly controversial. Despite the large number of dogs injured by them, many argue they can be safe. Even if they don't break into shards, they wear the teeth down. I know of no evidence showing not being given bones has harmed a dog. My 13 year old Lab never had a real bone in her life. Her teeth are in excellent shape, even still showing some of the 3 lobe pattern on the incisors. I happen to be sitting her 6 year old dog guide replacement today. His teeth are the same way. If anybody doesn't understand what I am talking about, here is a picture of an 8 month old's teeth:
Highly valuable guide and service dogs never get bones. It may not cost the price of a new car to replace a pet, but I see no reason for their owners to risk the emotional burden of giving their dog an unsafe chew.
Frankly I feel the dog guide and service dogs schools are in a position to know much more about dogs than most other sources of information. Not only do they have the experience with thousands and thousands of dogs, but they are continually testing different ideas to see what works and doesn't' work. They share what they learn with those caring for their dogs including me. There is a huge reservoir of dog guidance out there that has no scientific backing, and in fact is refuted by controlled testing. I can't believe anybody qualified to be writing a correspondence course on dog care would come here asking such a question.