As I stand on the runners of the dog sled trying to catch my breath, I look down at my dog sitting in his harness, facing the sled, just staring at me. There is no jumping enthusiasm, no barking, or straining—in fact, he looks annoyed. Somewhere along this journey things went terribly wrong. What started out as a relatively simple plan to teach Howie to pull a small sled, turned into a seemingly insurmountable feat.

About five years ago Howie entered our lives—a rowdy lab and shepherd mix puppy with endless energy. Even from his earliest days, our challenge has been trying to wear him out. We taught him to run on a treadmill, go on bike rides, hikes, and runs with us, and even carry his own back pack. Nothing really seemed to tire him out for long. My brother-in-law, commenting on his tireless energy, said, “You should…