My horse falls from canter into a trot what can I do?

A horse that falls from the canter into a trot without being asked is a horse that is not carrying himself — he is leaning on his forehand, running out of impulsion, or simply dropping out of the gait because maintaining it requires more physical effort than he is currently willing or able to sustain. The behavior is frustrating precisely because it feels like the horse is quitting on you, but in most cases the root cause is physical rather than attitudinal, and addressing the symptom by simply pushing the horse back up into the canter repeatedly without fixing the underlying issue produces a horse that requires constant leg to maintain any gait at all. The first question to ask is whether the horse is physically capable of sustaining the canter comfortably. A horse that is unfit, young, sore in his back or hocks, or being asked to work on footing that makes collection and balance difficult will drop to the trot as a physical relief mechanism rather than out of laziness or evasion. A horse that breaks consistently at the same point in a circle, after a certain number of strides, or on a specific lead is often telling you something about where his physical limitation or discomfort lies. Before you make this a training conversation, have your veterinarian evaluate the horse's hind end, back, and overall soundness. Assuming the horse is sound and fit enough for the work being asked, the canter break is almost always a collection and balance problem. A horse on his forehand cannot sustain the canter efficiently because the three-beat gait requires the hindquarters to carry and propel — when the hind end is trailing and the front end is carrying the load, the canter becomes mechanically exhausting and the trot is simply easier. The training fix is building collection and engagement rather than just adding more leg every time the horse breaks. Work on transitions — canter to trot and back to canter immediately — so that the horse learns to stay tuned in and ready rather than drifting mentally and physically between gaits. Circles are both a diagnostic and a corrective tool. A horse that breaks on a small circle but holds the canter on a large one is telling you he lacks the balance and collection to sustain the gait on a bent track with a shorter arc. Work him on larger circles where he can succeed, reward the sustained canter with a soft hand and a release, and gradually tighten the circle as his fitness and balance develop. Your own position and leg are part of the equation. A rider who goes passive the moment the canter is established — dropping the leg, softening entirely, and essentially handing the responsibility for maintaining the gait to the horse — is setting the horse up to break. Your leg should remain quietly present and alive throughout the canter, not squeezing constantly but ready to support the moment the horse's energy starts to fade. Catching the break before it happens is infinitely more effective than reacting to it after the horse is already in the trot.