The solution for many riders who have horses with "hard mouths" is to move up to a bigger bit. While this may provide a temporary fix, the problem will often resurface again. Here are a few tips to follow to be sure you are not accidentally training your horse to pull on the bit.
1. Only pick up on the reins if you want a response.
When you apply pressure to the bit in your horse's mouth by pulling on the reins, it causes some discomfort to the horse. "Pressure" in this regard, often means you are making the horse feel uncomfortable. Pressure is not always pleasant. We know that horses learn what the correct answer we are looking for is by the release of pressure. It's a reward. We apply pressure to motivate the horse to begin looking for the answer. He wants to find somewhere nicer to be. The pressure should be released when the horse finds the right answer.
With this is in mind, make sure you aren't putting unnecessary pressure on your horse's mouth. Only pick up on the reins if you want your horse to respond. People forget this, and keep their reins too short while they are riding or just siting on their horse during a break or while having a conversation with a friend. You are unknowingly applying pressure to the bit and the horse will eventually learn to ignore it because he's not getting a release. He may try to figure out the answer a few times, but will give up if you don't recognize it when he does. This is how horses develop "hard mouths".
2. Expect lightness through turns and when steering.
Another aspect that is commonly forgotten about is lightness during steering. For instance, let's say you ask your horse to change direction by picking up on your inside rein. You feel some resistance, but the horse makes a half circle and you're now going around the arena the opposite direction; so you release the rein. What you just taught your horse was to lean against pressure. Yes, his feet carried his body in the correct direction, but you rewarded the horse while he was pulling against the rein.
In this circumstance, I recommend keeping the horse on the circle until he softens to the pressure. You may have to go around several full circles before he feels soft. That's ok. It's better to wait and reward the right behavior. Use the leg on the inside of your circle in conjunction with your rein to encourage the horse to bend his ribs and engage his hindquarters. This will work to remove some resistance in the horse's body and help the horse soften his head and neck to your rein.
Anytime you steer or guide your horse, don't release the reins if he is pulling against you or leaning away. Stay in there until he feel nice and light. His feet can be going the right way and he can still be resisting the bit. He has to do both for it to be correct. He must turn or guide the way you want him to go while remaining soft on the bit in order to get a release.
3. Wait for softness before releasing the reins during downward transitions.
This is similar to the last point. If you ask your horse to halt and his feet stop moving, you must wait to relax your reins until the horse gives to the pressure. This is a common mistake riders make. As soon as the horse stops going forward they loosen the reins even if the horse is pulling hard against their hands. This is another way riders mistakenly teach their horses that they can fight the bit and get a reward.
Always make sure it feels like there is nothing in your hands before throwing the reins away. This is important to do during all downward transitions. From the canter to the trot, trot to the walk, etc. Just because the horse slows to the proper gait, does not mean it is the correct time to release your reins. You must maintain contact with the bit until the horse gives to your hands. Your timing is important. If you release too soon you teach the horse to pull on your hands, but on the other side, if you hold the pressure too long and miss when the horse responds correctly he will get frustrated and quit trying.
4. Reward effort during collection.
If you are asking for collection make sure you reward the horse when he gets off the bit. You don't want to constantly pull on the reins to keep his head where you want and ignore his efforts of softness. It needs to be a constant game of give and take. You pick up on the reins and if your horse feels nice, you instantly give back to him. Let him know that's what you want. You don't want him to stick his head down and lean against your hands. If you never release, he will eventually ignore the bit. The pressure never goes away; he can't escape it, so it starts to mean nothing to him.
Also remember to give a full release every once in a while while working on collection. If your horse carried himself well half way around the arena and stays real light in your hands, it'd be a good idea to loosen your reins all the way and let him have a complete release of pressure. His reward for being so nice is allowing him to stretch his neck and carry himself where he feels comfortable. If he feels like he's winning, he will try harder for you the next time. If he can't win, he'll quit.
Keep these tips in mind to ensure that you are not accidentally training your horse to fight the bit and ignore pressure. With consistency, you will have a horse that is very soft on the bit and responsive to your reins. Nothing feels better than a horse that is light in your hands.
Disclaimer: Of Horse! and sponsors do not endorse nor validate the accuracy of a blog post. Each article is the opinion of the blogger.