Join Date: Jul 2008
Location: British Columbia, Canada
It really depends. If the injury would cause discomfort for a mare to carry a foal, then yes, breeding her would be unethical. As would turning her into a broodmare (no matter how ewe-necked, sickle-hocked, hip-less, coarse, and fugly she may be) with the only reason being that she's unsound to ride and therefore is of no use to the owners would be unethical as well.
But if the mare is of excellent quality and the injury isn't genetic (impossible to be inhereted) and wouldn't create any extra unnecessary pain or stress on said mare, then I think that's perfectly fine.