If in doubt, always call your vet or the Animal Poison Line immediately.
Cooking makes bones brittle. They shatter into sharp shards that can puncture the mouth, throat, stomach, or intestines. Raw bones are generally safer but cooked chicken, pork, and fish bones are particularly dangerous. Never feed any cooked bone to a dog.
If your dog swallowed bone fragments, seek veterinary advice. Do not induce vomiting as bone shards can cause further damage coming back up.