How Do I Slow My Western Pleasure Horse Down?

Using Groundwork for Balance

1). Bridle your horse. Attach the longe line by passing it through the nearside bit ring, over the horse's head and clipping it to the outside bit ring.
2). Have the horse walk around the arena a few times to warm up. Do this in both directions, remembering to swap the longe line over onto the other bit ring when you change direction. Bring the horse onto a smaller circle, and have it trot. An unbalanced horse will find this difficult, so alternate the small circles with larger circles so as not to over-strain it.
3). Have your horse perform trot-to-walk and walk-to-trot transitions on the small circle. As its balance improves, you can include some canter/trot transitions as well. Carry out the exercises in both directions.

1). Mount your horse and ride around the arena a few times at the walk; then progress to the trot. Ride a small circle in each corner of the arena, pressing your inside leg against the girth to help the horse balance. An unbalanced horse will "fall out" through the shoulder rather than maintaining a true circle; you can block this by keeping a firm contact down the outside rein.
2). Perform several walk/trot transitions on the small circle. As your horse becomes more balanced, you can canter around the arena, slowing to a trot for the circles. Repeated transitions will help your horse bring its back legs underneath it to balance.
3). Ride a half-halt as you come into the circle. This will check a rushing horse and stop it from leaning on your hands for balance. Keeping a firm contact with the inside rein, squeeze and lift your outside hand while pushing your seat bones down into the saddle. Allow your weight to go slightly backward by bringing your shoulders down and back. Ride a half-halt before every transition and just before every circle to encourage your horse to carry itself properly.