How to start an ex-racehorse to jumping?

Starting an ex-racehorse over jumps is in many ways one of the most natural second-career transitions available to off-track Thoroughbreds, because the Thoroughbred breed was developed specifically for the athletic demands that jumping requires — scope, boldness, elasticity, natural impulsion, and the genuine forward courage that approaches a fence without backing off. Many ex-racehorses take to jumping with an ease and enthusiasm that surprises handlers who expected a lengthy desensitization process. The physical evaluation is mandatory before any jumping work begins, specifically comprehensive around the front limbs, hocks, and back — the areas most stressed by both racing and the additional impact demands of jumping. A horse with front fetlock changes, active hock arthritis, or back soreness will find the concussive demands of jumping significantly more difficult to manage than a horse with a clean physical evaluation. The flatwork foundation must be genuinely established before any jumping is introduced, regardless of how physically capable the horse appears. The specific flatwork qualities that jumping requires are genuine forward off a light leg, reliable transitions between and within gaits, the ability to shorten and lengthen the stride in response to the rider's aids, basic straightness, and acceptance of a consistent contact that the rider can use to half-halt and organize the horse for the approach to a fence. Ground poles are the starting point. A horse that has spent his career galloping over maintained obstacle-free track surfaces has not developed the proprioceptive awareness and stride regulation that negotiating poles develops. Build from a single pole to two poles, then to a line of trot poles spaced at the appropriate distance for the horse's natural stride length, working until the horse trots through with consistent adjustable rhythm. The first raised obstacle should be a cross-rail set at its lowest possible height approached from a consistent forward trot. The ex-racehorse's specific tendency to rush — to accelerate toward and away from fences — is the technical problem most commonly encountered and requires the most specific systematic work to address. Gymnastic lines — bounce combinations, one-stride lines, and two-stride lines — teach the horse to regulate his stride through the fence rather than accelerating through it. Build height and complexity progressively over weeks and months rather than escalating quickly because the ex-racehorse's natural scope makes larger fences seem easily achievable. The physical development of muscles and connective tissue that support correct repeatable jumping at higher heights is a gradual process that cannot be shortcut by the horse's natural ability.