For such a quiet animal, the horse's mouth can tell quite a lot. It's the point of control for many a rider, and it is the evaluator of age for many a trader. Good manners preclude looking into a gifted mount's mouth, however there will come a time when concern for its teeth is necessary.
When should you be concerned with your horse's teeth? Examining the newborn foal's mouth and the few teeth they are born with may help establish plans to help them grow out of over-bites or under-bites. New deciduous or baby teeth come in throughout the first year to two of live at which time permanent teeth erupt replacing most of the baby teeth until the horse is 5 years old. Geldings and stallions, and sometimes mares, will erupt canine teeth at about 6 years old. During these times, like any teething toddler, there may be bouts of discomfort and assistance may be needed to help remove dangling deciduous teeth referred to as caps.
The permanent teeth are intended to stay in place for the life of the horse. Permanent teeth are approximately four inches long and continue to erupt as the horse grinds them down grazing and eating. The six incisors on the top and bottom jaws come together to nip and cut forage. The three premolars and three molars on each side of each jaw grind together in an elliptical fashion to break the horse's diet into small, digestible bits. Because the lower jaw is slightly narrower than the upper jaw, this creates a normal wear pattern where the cheek side of the upper teeth and the tongue side of the lower teeth develop points.
The canine teeth in male horses are remnants of days when stallions fought to build and keep their mare bands. The canine teeth should not be confused with the wolf teeth, which are vestigial premolars left over from equine ancestors that roamed the forest.
In young horses, though debatable, wolf teeth often are removed to prevent problems with the bit while starting training. Additionally, while examining horses less than 5 years old, removal of caps may be necessary to keep the mouth in good balance. If caps do not fall off on their own, they may impede the eruption of the opposite tooth which can create a "step" mouth in which one tooth is much higher than the others. Pain, age, diet and other influences may cause horses to develop a "wave" mouth or hooks and ramps at the ends of the dental arcades. Fractured teeth may need to be removed to ease pain and provide better chewing. During "floating" or dental equilibration, these abnormalities along with the sharp points that naturally develop can be prevented or corrected. Once severe abnormalities occur, they may take months to years to fully correct.
Examination of the horse's mouth should be performed at least annually to help prevent trouble. Issues in the mouth may present as frequent colic, loosing weight, choke, becoming head shy, difficulty reining, rearing, and other signs of discomfort around their head and mouth. Timely recognition of issues in the mouth can save time, pain, and expense in keeping your horse healthy and working.