Although you can give your dog a deer bone you find in the woods despite the fact that they are safe to eat you should not.
Theres nothing wrong with this option because its free and looks like a nice treat for your dog but it isnot safe.
There is an age-related reason for this.
There could be a lot of bacteria on the bone because you have no idea how long its been there. In addition to that the older you get the more brittle your bones become.
The teeth of dogs may be damaged or broken if they chew on brittle bones but they may also choke if they swallow the bones.