Size matters!
Consider the size and shape of the bit as well . The structure of the mouth , and the space that`s available for carrying a bit , varies between horses .Because a horse`s teeth continually erupt , his mouth will change shape as he ages . The older the horse , the more room there will be in his mouth for the bit, therefore , more complicated mouthpieces can be introduced as the horse matures , and also as his level of training increases .
It shouldn`t be assumed that bitless bridles give the horse`s mouth an easy ride! Although there is no metal inside the horse`s mouth , pulling on the reins nevertheless creates pressure along the outer edges of the horse`s cheeks . As a result , the inner surface of the horse`s cheeks are pressed against the outer edges of the upper cheek teeth . So it`s important that these teeth have no sharp enamel points , which would make the soft tissues in the mouth vulnerable to laceration . Likewise , “ baby “ premolars that fail to shed , have the same effect on the cheek tissues when sideways pressure is applied .
An incorrectly fitted bit can cause tissue to become “ bunched “ between the bit and first lower cheek tooth , where it may be pinched or lacerated large , painful ulcers can also form under the mouthpiece , irritating the tissue every time the bit moves .
Because horses tend to push into pain , this may cause the horse to lean onto the bit on the affected side.