How do you fix a horse that refuses to change leads or ignores the change aid?

A horse that refuses the lead change or consistently ignores the change aid has either not learned the aid clearly enough to respond to it, has developed a resistance or evasion to the change, or has a physical reason — soreness, asymmetry, or balance problem — that makes the change uncomfortable. Identifying which cause is present determines the correct approach. Clinton Anderson's first step with a change-resistant horse is always to check for physical causes. Back soreness, hock pain, stifle problems, and asymmetrical muscle development can all make flying lead changes uncomfortable or impossible, and a horse that was changing willingly and has stopped is communicating something worth investigating physically before any training correction is applied. If the horse is physically sound, Anderson returns to the prerequisite work. A horse that will not change leads on the figure eight typically has a balance or collection deficiency that makes the change mechanically difficult, or has not confirmed its lead departures sufficiently for the more demanding flying change to build on. Returning to trot-to-lope departures, confirming them on both leads, and rebuilding the figure eight work from the beginning often resolves the refusal by reestablishing the correct foundation. For horses that understand the change but evade it — that anticipate the figure eight and begin to swap leads spontaneously or that brace and rush when the change aid is applied — Anderson addresses the evasion directly. He schools the horse specifically through the figure eight center without asking for a change, riding through the change point on a specific lead intentionally, so the horse learns that the figure eight center does not automatically mean a lead change. This removes the anticipation and reestablishes that the change happens only when the specific aid is given.