The Appendix Quarter Horse is a first-generation cross between a Thoroughbred and an American Quarter Horse (or between registered and appendix American Quarter Horses). The appendix registry began in Texas in 1949 when the American Quarter Racing and the National Quarter Horse Breeders associations merged. Breeders saw it as an opportunity to create larger, faster, more refined horses.

Horses listed in the appendix may be entered in competition, but offspring are not eligible for full AQHA registration unless the Appendix horse meets strict conformational criteria and is shown or raced successfully, earning its way into the permanent studbook.

Since Quarter Horse and Thoroughbred crosses continue to enter the official registry of the American Quarter Horse breed, this creates a continual gene flow from the Thoroughbred breed into the American Quarter Horse breed, which has altered many of the characteristics that typified the breed in the early years of its formation. Some breeders argue that the continued infusion of Thoroughbred bloodlines is beginning to compromise the integrity of the breed standard, favour the earlier style of horse, and have as a result created several separate organizations to promote and register “Foundation” Quarter Horses.

CLIX photo


As the Appendix horse is a cross between the Thoroughbred and Quarter Horse, characteristics from both breeds exist to varying degrees. Stock-type horses tend to be a little shorter and compact, with greater muscle mass, while still being agile. Racing-type are taller and leaner with smoother muscling.

Appendix horses stand between 15-17 hands and can be found in a variety of colours including sorrel, palomino, black, bay, grey, chestnut, dun, buckskin and roan.

With a personality and versatility similar to the Quarter Horse, these animals usually have an even disposition, are social and generally easy keepers. Any competitive ‘hotness’ can usually be directed into their work, especially speed sports such as racing or gaming.


All-round multi-purpose horses, Appendix QHs can be used as show horses, pleasure horses, race horses, and as working cattle horses.

For more information:
American Appendix Horse Association Inc.

Bob Langrish photo