About a month ago, my husband and I got an 18 month old German Shepherd/Dutch Shepherd cross. I have a five year old son who won't be starting school for another three weeks. I've tried walking him on leash with my son, and it's just too difficult. My son gets tired after a few blocks, and my new dog really benefits from a good 45 minute walk or longer. My son also distracts me, and I sometimes lose the calm/assertive state needed to keep the new dog at ease. The easiest way for my dog to get exercise is to take him to the dog park. Most of the time, he plays really well with the other dogs. My only complaint is the neck biting thing he does. There are three GSD owners I see there on a regular basis. They told me this is GSD behavior and didn't seem to mind it. I still would say "No bite." If he didn't listen, I would put him into time out until he lowered his energy. However, twice this week, he's escalated the behavior to pinning and actual choking. He was playing fine with a pit bull mix and a husky. The husky left. The pit bull mix enticed my dog to chase him. My dog pinned him at the throat, and I could hear the pit bull mix gasping for breath. I immediately removed my dog from the situation, put a leash on him, and apologized to the owner. He had two good days. Then, he did this again with an Australian Shepherd he was chasing. I did the same thing. Leash until he calmed down. I read a few articles about prey drive, and I'm wondering if the "chasing" is too high energy for him? We've been working on his recall, and he listens pretty well at the dog park. I've even had a few people comment that he seems to listen better than most of the dogs there. Unfortunately, when he gets high energy during a game of chase, it's almost like he gets fixated. I hope I don't sound like a complete idiot here. I have a 13 year old boxer that I've had since he was a puppy, and I took him through obedience training to keep his 90 pounds in check. I haven't had a young dog in a while, and this is my first GSD. My husband had a GSD when we met, but the GSD was an "old man" by the time I came into the picture. Once my son starts school, I'll have more time to really work with him on leash. My in-laws were in town recently, and I was able to walk him by myself. I took a clicker and treats and worked on loose leash walking. I can't believe what a difference that made in just a few days. He really is a smart dog. I've taken him through a few of the agility obstacles at the dog park, and I'm amazed at how quickly he picks things up. Show him something once or twice, and he's got it. I'm so happy I found this forum, and I welcome any advice! Thank you in advance!!