Douglas Harper's Etymology Dictionary
Usage examples of "race-horse".
He built them strong and solid, with walls fitted to repel the assaults of the weather, and possibly those of men as well, for the Boones in their day had been mighty owners of race-horses at a time when men with money at stake did not stick at trifles, and it was prudent to see to it that the spot where the favourite was housed had something of the nature of a fortress.
But when we compare the dray-horse and race-horse, the dromedary and camel, the various breeds of sheep fitted either for cultivated land or mountain pasture, with the wool of one breed good for one purpose, and that of another breed for another purpose.
But there is not a shadow of evidence in favour of this view: to assert that we could not breed our cart and race-horses, long and short-horned cattle and poultry of various breeds, and esculent vegetables, for an almost infinite number of generations, would be opposed to all experience.