No carting practice yesterday as there was a bear in my neighbor's yard near the hill where I've been practicing--and that might have been a bit of a distraction (for me. It appears this bear has previously bedded down near my bird bath at night--ah, spring in Montana when one lives in prime grizzly/black bear habitat. Here, you are careful not to put out birdseed--or anything odoriferous--a favorite food of those rascally bears.)
I measured the distance between Taz's shafts and her harness; two inches on each side--or the width of three (of my) fingers on each side--so the cart seems to fit her according to that dimension. Thanks for all your suggestions. Onwards (i.e., backwards)! Christy Kabler