When I was in the hotel in the Chicago area, before and after our meeting with Rachel, we put Graham on the treadmill in the hotel workout room It was actually not to get him excersised, it was more of a means to make us laugh, but he seemed to get the hang of it. What my mom did (she was the one traveling with me) was go to the front of the treadmill and call Graham, and I just held his leash steady and made sure he ran streight and not off the edges.

They have special made treadmills for dogs with rails that prevent an escape, and a spot to attach the leash so the pup can't stop and run off the back...it has to keep going. I am sure your treadmill would work but you would have to get them trained on it first. Might take them a little while to get the hang of it....and I would for sure get Don's help until they were used to it to prevent accident.