Hello! We have 6 months old golden retriever. He's very hyper. We have problems with going out with him. When door is opened, he shoots out of home like a cannonball, almost crashing with head in neighboor's door. We don't understand how to teach him go out more calmly. Next problem is going down the stairs. He runs down like crazy, almost flying. Our leash isn't so long to cover all steps, so every time we are in danger to fall down and break something. We are trying to go down on short leash, but he never stops pulling like crazy, eventually hanging on leash and heavily breathing. After he runs outside, he calms down and starts to obey us. We are trying to calm down him at home, just before going out, but his behavior on stairs does not change. Could anyone recomend any training techniques, how to walk out of the door and down the stairs more calmly, please?