“My brother,” said he, “do not ride to–day / The dapple, as you’re wont; but mount the horse / Which I have chosen for thee.
2004, D Caroline Coile, http://books.google.com/books?ie=UTF-8&hl=en&vid=ISBN0764126733&id=vmTgPakg8nUC&pg=PA21&lpg=PA21&sig=5r0UWTYWxGcZayQlGiP4v3b1ajU
Some well-intentioned breeders inadvertently breed two dapples together because occasionally a dapple will have so few patches of mottled coloration it appears undappled.
adjective
Having a mottled or spotted skin or coat, dappled.