How do you train a dressage horse that has learned bad habits from previous incorrect training?

Retraining a horse that has developed bad habits from previous incorrect training requires both specific gymnastic work to address the physical patterns the incorrect training has created and a careful rebuilding of the horse's training relationship and confidence that may have been damaged by whatever approach produced the problems. The first step is an honest assessment of what specifically is wrong — not just the behavioral symptoms but the underlying training issues they reflect. A horse that is above the bit and tense has a suppleness and contact problem that reflects insufficient development of throughness; a horse that is behind the leg has learned that ignoring leg pressure eventually causes it to stop; a horse that resists lateral work has either a physical issue or an insufficient foundation in the prerequisite exercises. The general principle is to go back to the last point in the horse's training where the foundation was genuinely correct and rebuild from there, rather than attempting to fix problems at the level where they appear without addressing the underlying preparation that is missing. This often means returning to exercises that appear too basic for the horse's apparent level — working on a contact-seeking stretch in long and low work for a horse above the bit, returning to basic leg responsiveness exercises for a horse behind the leg — and genuinely confirming these foundational qualities before returning to more advanced work. Warwick Schiller's insight that horses with bad training habits often have underlying emotional issues — tension, shutdown, or anxiety that the training approach created — is particularly relevant for retraining: sometimes the most important work is not gymnastic correction but rebuilding the horse's trust in the training relationship through patient, low-pressure work that allows the horse to rediscover that training can be comprehensible and rewarding rather than confusing and aversive.