I'm an adult volunteer working with a local 4-H group, and we're trying to break a mini donkey to drive for one of the girl's fair projects. I have my old mini harness and cart, plus there is a shetland/hackney cart at the barn the donkey is at. With some work, I think I can get the harness to fit (long back, short girth), but the cart is another story. The Shetland cart is too big (width of shafts and length of shafts), the mini cart is too small (width of shafts). The donkey is pretty portly and has mainly been a petting zoo animal, so her belly is...well...big and low and though the shafts don't indent her belly - there is zero room between her belly and the shaft. So the question is, would you rather have a too big cart where she is swimming or a too-small cart that could rub? I'm also hoping that with some exercise, she can trim down but being that her main "job" is petting zoo...I'm not sure how reasonable that is? Getting another cart isn't really an option - it's a volunteer/4-H barn/community farm.