He is resource guarding. You need to teach him to drop things on command. Start by trading for a higher value treat. Give him a toy, and then ask him to drop it and trade for a higher value treat or toy.
A good thing for everyone to practice is to go up to your dog and ask to see their Kong/Stick/Toy. Pick it up, look at it, and give it back. Do this periodically so the dog learns that you aren't going to steal their toy. |