Equineline.com, the industry leader for complete, comprehensive, accurate and timely pedigree, racing information and more for both Thoroughbreds and Quarter Horses.

The Jockey Club is the breed registry for all Thoroughbred horses in North America. As such, it is responsible for maintaining The American Stud Book, which includes all Thoroughbreds foaled in the United States, Canada and Puerto Rico as well as Thoroughbreds imported into those countries from nations around the world that maintain similar Thoroughbred registries.

Thoroughbred Pedigree Database

The Retired Racehorse Training Project is a new web site that will include a directory of trainers who work successfully with Thoroughbreds off the track. Founded by Maryland-based trainer Steuart Pittman, his wife Erin Pittman and a board of directors that is committed to expanding the market for retired racehorses.

In addition to the above resources, here is an excellent article written by Deb Bennett, Ph.D. called "TIMING AND RATE OF SKELETAL MATURATION IN HORSES, With Comments on Starting Young Horses and the State of the Industry"