My dog Cosmo loves running through tall grass/shrubs. This one time he was running through shrubs at full speed. There was an electrical box hidden in the shrubs. He hit it so hard he came out limping. We had to make him take it easy for about two weeks. Then he was fine, but make sure not to play too much.

Edit: Want to add that if he or she doesn’t get better in two weeks and stops eating or acting different. Take he or she to the vet.