Shaping Your Horse's Canter

your gas pedal is working the horse should go forward immediately when asked every time everywhere. Finally ask yourself if he flexes and gives to any pressure from the bit or if he resists crosses his jaw or raises his head?
With these tools available when you send the horse forward into the resistance of your hands he will collect his frame and give to the bit rather than spill out the back doo
Shaping in learning science refers to gradually teaching a new behaviour through reinforcement until the target behaviour is achieved. Have you ever played the Hot and Cold game? As the player gets closer to the prize you yell Hotter! telling him that hes on the right track. When my horse is on the right track I reward his approximation of the behaviour. I call this rewarding the thought or rewarding a try.
Sometimes the right try happens by accident as if the horse is guessing. When teaching your horse to shorten his canter stride reward him at the moment he starts to shift his weight back in an attempt to collect. Many horses respond at first by raising their heads speeding up or breaking to trot. Your job is to block all the wrong tries and reward the right ones.
Back to the Box
Picture a threedimensional box around your horse. To slow the canter you must resist every time your horse lengthens or quickens his stride picture him meeting the front of the box while maintaining the canter rhythm with your leg and seat the back of the box. Provide freedom every time he slows his stride in the box.
Your horse will eventually see a pattern developing and will seek the freedom of remaining in a slow canter. This sounds simplistic but its pretty common to see a rider hanging on her horses mouth tug of war style while he motors around oblivious to her.
Motivation
Its important that the resistance you use to slow your horse is enough to get his attention. When slowing your horse establish firm contact by sliding your elbows back with hands directed in a straight line