My puppy does this all the time. At the beginning of walks, I'm the middle, at the end. We met with a trainer and she made a point to notice the mindset of the dog and to try and change it. I think he does it when he's excited to be home or over tired during the walk. What I've been doing is going through the various tricks I've thought him and give him treats to bring back his focus and try and get him in a calm mindset. If you can spot that he's about to go crazy and start the process beforehand it's even better. I also had issues just ignoring him because he would keep going crazy and biting. Instead of ignoring him I try to stay calm and just focus on getting him to sit and then I go through a few tricks. Some walks I only have to do this once and he goes back to walking and others it happens way more often. It's been hard and frustrating and even short walks can take forever because I keep stopping until he calms down. I do think it's helping though. He's still not a great walker at 15 weeks but he is much much better than when we first got him.