Hello and thank you for asking your question on just answer. My name isXXXXX will try to help.
I am going to tell you the absolute worst that could happen. But hopefully it will not. The bone could have sharp edges and pierce his stomach or intestines and cause bleeding. The bone could also lodge in his stomach or intestines and cause a gastrointestinal blockage. This would need to be resolved with surgical intervention.
So if he is acting fine, you do not need to do anything now. Over the next 3 days, you are going to monitor his appetite. If he stops eating and drinking then that is a warning sign that he may have gastrointestinal blockage from the bone.
Check his gum color now. If the gums become very pale, or he becomes very lethargic, he may have internal bleeding. The same applies if he vomits or defecates blood.
If he gets a blockage, he will not be able to keep food or water down. Everything he eats will come back up.
If you notice any of these signs, he needs to see the vet right away.
You can give him one teaspoon of the metamucil, at every meal, to try and increase fiber to bulk things up and move them through.
I hope this helps.