The horse is herbivorous, meaning its diet is composed of plants and plant materials. Consequently, its teeth have evolved to accommodate the changes, specifically the wearing of tooth surfaces that result from the fibrous diet they consume.
Similar to what occurs in other species, the teeth in a foal undergo modifications as the foal ages. The early teeth are called deciduous teeth. Replacement with the larger permanent teeth and the emergence of molars (and canine teeth, which are much more common in males than females) have occurred by the time the horse is approximately 5 years of age.
A regular dental examination can benefit the young horse as well as the older horse. In the young horse, the veterinarian checks periodically that teeth are appearing (erupting) on schedule as they should. The veterinarian can also check for the presence of “wolf teeth,” which are small first premolars more common in males than in females. Their removal may be recommended. The veterinarian will also evaluate the conformation or shape of your horse’s mouth and jaw bones. Abnormal shape can interfere with their function, and the result may be the inability of the horse to effectively graze and/or chew. As the young horse begins to be ridden and trained, certain dental issues can produce mouth pain, which may be accentuated by the presence of the bit.
Older horses can suffer from a variety of dental problems. Gingivitis (inflammation of the gums), irregular wear and tooth loss would not be uncommon. Depending on the stage and severity of the disease, affected animals can present with a variety of signs, such as bad breath, salivation, dropped boluses (“cuds”) of semi-chewed food, and weight loss. The horse is likely to eat slowly, and there may be incompletely digested feed evident in the manure.
Horses with dental disease can experience tooth sensitivity to temperature extremes. As an example, they may be apprehensive to drink cold water, which could increase the risk of dehydration and constipation occurring.
In some horses, mouth/tooth problems are manifested as behaviour changes when they are being either ridden or driven. Such horses may be reluctant to take the bit, they may exhibit head-shaking as they are being ridden or driven, or they may be otherwise resistant to what is being asked of them.