Session 22 (03/16/2013) - Raised the DW to 24" and changed its directional orientation. Was very pleased at how well Belle did. 9 successes out of 11 reps. Belle was sitting on the DW for the beginning of each rep. Tried varying my position and movement a little bit each time--nothing drastic though. DW on my left and we were running toward the NW.
Session 23 (03/17/2013) - I ran with Belle on right today heading SE and toward the fence. When I viewed the video in slo-mo, I was dismayed to see she was bringing her left foreleg across the midline of her body. Once I had seen it in slo-mo, I was able to see in real time, the effect it was having on her path on the DW. Over the last year, I have noticed she is beginning to wing inward with her left front, but it usually isn't this pronounced. I checked her over but couldn't find anything except that her toenails were in need of clipping. I clipped them back and we won't do any DW work for a day or two and see if the problem persists.