It is thought the equine ancestor lived some 55million years ago and is believed to have been 10 to 12 inches tall. They had short crowned ‘brachydont’ teeth similar to that of a human. The teeth were more suited for the softer fruit like diet they foraged on. Evolutionary changes have created a dramatic change to horses as we know them. Their dentition has changed because of the diet they now consume. As they masticate (chew) these high cellulose (sugar) coarse fibres a more suited ‘hypsodont’ tooth was required. Hypsodont teeth erupt throughout the horse’s life time, wearing at a rate of approximately 3mm a year.
The horse masticates its food in a circular motion. In a balanced normal mouth only one side of the dental arcade is in contact at any one time. However, through domestication and unconsidered breeding lines this is not always the case. Unfortunately for the horse in a very domesticated environment, the dention can suffer because we impose restrictions on grazing times and movement which all impact the natural positioning of the head whilst eating. It has been proven by scientific research that hard concentrated feeds, shorten and changes the mastication cycle, creating more of a ‘chomping’ type movement. This quite often increases the sharp edges in the mouth, thus effecting welfare and performance in a shorter space of time.
In a lot of breeding programmes very little consideration is given to the congenital issues regarding dentition. This may be because there is a greater need for the ‘type’ of equine athlete we require for today’s high performance industry. It would be fair to say in most cases if poor dentition is adequately maintained from a young age, welfare and performance will not be affected, unfortunately this is not always the case.
Horses that are fortunate to have ‘normal’ mouths still require dental examination to monitor any pathology that may arise between examinations. In these cases we still expect to aid welfare and performance by removing sharp edges and rounding the molars situated directly behind the bit (bit seating). Even after a few treatments a small difference can be felt by the rider which is rewarding us.