May 27

Written by: Surgi-Care Center for Horses
5/27/2011 5:22 AM 

Dental health is a very important aspect of the overall care and condition of your horse. For this reason, it is important that you understand the anatomy and problems that can occur in your horse’s mouth and what to do about these problems.

The horse has two types of teeth: deciduous and permanent. Deciduous teeth, or baby teeth, are the first teeth that erupt (break out of the gums). Permanent teeth take the place of deciduous teeth and will remain in the mouth for the life of the horse. There are several types of teeth: incisors, canines, premolars, and molars. Incisors are the teeth that are present in the front of the horse’s mouth and the incisors enable your horse to pick grass. Canines are the teeth immediately behind the incisors in the area of the “bar” and are most often present in males. These teeth are very sharp in younger horses and can be used as weapons. Canines become more rounded as the horse ages. Premolars are the first cheek teeth. These are large teeth along the sides of the mouth and the first premolars are also known as “wolf teeth”. Molars are the last teeth along the sides of the mouth. The premolars and molars are used to grind food into small particles which can then be digested by the horse.

Dental disease in your horse can be viewed as weight loss, dropping food or quidding, swelling on face, halitosis (bad odor from mouth), excessive salivation (drooling), head shaking, bit problems, large food particles in manure, colic, drainage from mouth or nose, or difficulty swallowing. The horse chews its food by moving the jaw from side to side in a circle. The horse opens its mouth, moves the jaw to one side, and then closed the mouth. The ability to move the jaw to one side is decreased if dental abnormalities are present. Thus, mastication (or chewing) of food is incomplete and digestion and absorption of minerals and nutrients is also decreased. Routine dental prophylaxis should be performed on your horse to prevent and treat problems which decrease your horse’s ability to masticate food properly.

Incisor problems can prevent the molars from meeting properly which is evidenced as decreased feed grinding. Parrot mouth or an overbite is a congenital (foals are born with the problem) trait which interferes with correct premolar and molar contact. The incisors can also wear incorrectly due to missing teeth or other abnormalities which results in the inability of the cheek teeth to grind feed correctly. The incisors can also be offset (long on one side and short on the other), have a dorsal curvature (frown), or a ventral curvature (smile). These problems can be addressed by regular dental floating to somewhat correct the anatomic variation in the incisors.

The “wolf teeth” or first premolars can interfere with the bit due to their anatomic location in the area of the bar. A horse can have from 0-4 “wolf teeth”, which are most often found on the upper jaw. These teeth can remain unerrupted (under the gums) and appear as a bump on the gums in the area of the bar that can be painful to the horse and can cause infection. These teeth are usually removed to prevent any training problems associated with their anatomic location in the mouth. As a horse ages, the teeth grow until the entire reserve tooth is gone. A horse usually has molars until 30 to 35 years of age when the reserve tooth is no longer present. Routine dental care and examination in your elderly horse is very important to determine if feed changes should be made which will enable the nutrition of your horse to remain adequate for the remainder of its life.

The most common problem noted on routine dental examinations is sharp ridges on the outside of the upper molars and the inside of the lower molars. These points can cut into the gums and cause pain and infection. Other common abnormalities include hooks and ramps which occur on the front and back of the upper and lower rows of teeth. These abnormalities are caused by an abnormal chewing cycle where the entire surface of the molar does not gain contact with the opposite side. This problem can prevent further jaw movement and lead to worsening hooks and ramps. Caps occur in young horses and are a remnant of the deciduous tooth which remains over the permanent tooth. This abnormality can cause pain when eating, dental abnormalities later in life (such as a “step mouth”), impacted teeth, and can become infected. Remaining caps should be removed by your veterinarian. Another common dental abnormality which occurs when the molars are not perfectly aligned is accentuated transverse ridges. These are sharp points on the grinding surface of the teeth which are not in normal wear due to the malalignment of the teeth. These common dental findings can be corrected and prevented by regular dental examination and floating.

A “wave mouth” occurs when an entire row of teeth are uneven. The tooth line forms an “S” and interferes with the normal mastication of food. This abnormality can occur due to caps, missing teeth, or large hooks and ramps. Another dental abnormality that occurs when teeth are missing is a “step mouth”. The tooth opposite the missing one will continue to grow and can puncture the gum where the missing tooth would have originated. These overgrown teeth interfere with the normal gliding of the teeth in food mastication. This abnormality should be corrected by reshaping the tooth until it is parallel with the remaining teeth on that arcade (line of teeth).

Abscesses can occur due to missing teeth, loose teeth, and dental impactions. If teeth are missing, loose, or impacted, food can accumulate in the area of the abnormality and form an abscess. Clinical signs include drainage from the tooth itself, odor from the mouth, decreased appetite, head shaking, dropping food, pain when eating, and, if the root of the tooth communicates with the sinus, signs of sinusitis which are sneezing, fetid odor, purulent nasal discharge, and sinus pain.

Routine dental care of your horse can prevent and treat many of the above problems and enable your horse to live a long, healthy life. If you notice any abnormal behavior or signs of oral pain which could be attributed to a dental abnormality, please contact your regular veterinarian to schedule a dental examination.

Contact Surgi-Care Center for Horses at 813-643-7177 or email lkuebelbeck@surgi-carecenter.com with any questions regarding this topic.