[header] How to diagnose broken bones in dogs [title] Consider recent events. [step] Dogs can break bones as a result of being hit by a car, falling from a height, getting a leg caught in a hole, or from being stepped on (small dogs). Think about recent events that may have injured your dog. 
If your dog went missing for a few days and then came back limping, then there is a good chance that he was injured. [substeps] If your dog has just been hit by a car or if he has other signs of a visible injury (bleeding, bone sticking out, etc.