Instructions
Relax your body tension while riding. Continue to make contact with your legs, but lay them lightly against the pony's sides. When your pony senses tension from you, it tends to increase speed.
Canter your pony in small circles to force it to slow down as it turns.
Apply a half-halt, or check on the reins, right as your pony's leading foreleg lands and its hind legs are underneath its belly. This is called the moment of suspension during a canter. Apply slight pressure, but not enough to fully halt the pony.
Release the reins quickly after the pony responds to the check. You may need to apply a series of half-halts, but do not apply constant pressure.
Allow the pony to canter for only three to four strides before slowing it to a walk. Walk the pony for several minutes, canter for three to four strides and then walk again. This may convince your pony that there is no point to rushing off into a very fast canter.
How to Slow Down My Pony's Canter
Some ponies canter quickly because they are frightened or their tack fits poorly or painfully. Others may be inclined to bolt if they sense that you are nervous or if you ride them inappropriately. Aside from calming your pony and correcting your riding posture, you may need to re-train your pony to canter at an appropriate speed. Be persistent and patient while adjusting the pony's canter; it may take some time for the pony to catch on to your new routine.