His brother, however, unwilling to part with him so soon, proposes to ride with him in a light open carriage to the place where he will bait for the night, and there remain with him until morning, a servant riding for so much of the journey on the thoroughbred old grey from Chesney Wold.
There are no more uses of "thoroughbred" in the book.
Show samples from other sources
A feral hog, some hornets, and a prodigy led me through the woods so that I might stumble upon the first girl I ever kissed riding "TOC like he’s a thoroughbred next to the grave of an Austro-Hungarian Archduke.
John Green -- An Abundance of Katherines
There would be burnished, stick-legged Thoroughbreds, their jockeys in billowing bright silks, careering past.