My dog is ten months and I have been trying to train her to walk properly on a leash since she was a baby. We walk a couple times a week and she is always excited and pulling. I keep her on a short string ( I have a retractable leash) but it doesn't seem to help, she just chokes herself pulling. I also try to snap her back, but she is pretty strong and I end up hurting my arm instead. Saying "no!" works for a second then she starts right back up.After ten or fifteen minutes of walking, she is fine and stays mostly by my side. But how can I keep her by my side and not pulling for the whole walk?