…who knew Don Quixote, he said aloud, "The fact is, my good fellow, that I am tired collecting such a number of opinions, for I find that there is not one of whom I ask what I desire to know, who does not tell me that it is absurd to say that this is the pack-saddle of an ass, and not the caparison of a horse, nay, of a thoroughbred horse; so you must submit, for, in spite of you and your ass, this is a caparison and no pack-saddle, and you have stated and proved your case very badly."
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.