Hi! Im a first time dog owner. We got Sonny when he was 8 weeks old he is now 15 months. He is such a sweet boy. The most gental and playful pup. He has recently shown some rough play at the dog park. And some difficlty walking on a leash. Im looking for guidence on how to stop him from pulling when being walked and when would be a good age to get him fixed, if at all? Any advice, articles, or prior posts would be much appreciated!