Dental Care in HorsesBy Kentucky Equine Research Staff · October 29, 2002
The teeth play an important role in equine nutrition. Horses bite off mouthfuls of grass with the incisors (front teeth) and chew with a side-to-side grinding action of the molars (rear teeth). Chewing breaks up hard grains in the feed and mixes saliva into everything the horse eats. As the first step in the digestive process, healthy teeth allow the horse to get the maximum benefit from his diet.
By the age of five, a horse's deciduous teeth are replaced with permanent teeth that continue to grow throughout the life of the horse. The chewing surface of a tooth wears away at about the same rate the tooth grows (about 1.5 to 2 millimeters a year).
What problems can occur with a horse's teeth?
• Uneven wear. Because the lower jaw is narrower than the upper jaw, the molars do not meet squarely. Over the course of time, the outer edges of the top teeth and the inner edges of the bottom teeth develop sharp points that can irritate the cheeks, gums, and tongue.
• Malformations. The lower jaw may be too short, causing an overbite (“parrot mouth”), or too long, causing an underbite (“monkey mouth” or “sow mouth”). These conditions make it more difficult for the horse to chew effectively, and uncorrected malformations allow the teeth to wear in a pattern that forces the jaw into a more severe misalignment.
• Missing teeth. Besides affecting the horse's chewing ability, a missing tooth causes an uneven wear pattern because the tooth opposite the gap grows too long and may interfere with jaw movement or bit action.
• Crooked or broken teeth. Food tends to collect around broken or misaligned teeth, and gum or tooth infections can result.
• Retained caps. Baby teeth are usually forced out as the permanent teeth grow into place. If the roots of a baby tooth become lodged around the permanent crown, the deciduous tooth stays in the mouth as a cap, causing irritation and interfering with chewing.
• Wolf teeth. These very small, shallow-rooted teeth erupt just in front of the permanent molars in about 90% of young horses. If the wolf teeth are not removed, pressure from the bit may cause pain and irritation.
How might I know that my horse's teeth need to be checked?
A horse with dental problems might drop hay or feed out of his mouth, lose weight, back off his feed, drool profusely, or refuse to drink cold water. The owner might see bloody saliva or detect an unpleasant odor from the mouth or nostrils. Repeated yawning or holding the head in a stretched or tilted position after eating might also be signs that food is being caught in or between the horse's teeth. Behavior such as head tossing, bolting, bucking, or refusing to be bridled, especially in a horse that has previously shown good manners, may be due to pain caused by the bit hitting sore teeth or gums.
What dental care do horses need?
Even before all the teeth erupt, young foals should be examined by a veterinarian or equine dentist to check alignment of the jaws. Some jaw malformations can be minimized if corrective measures are begun at a very early age. A schedule of regular dental care is important for all young horses because sharp edges can develop very quickly on baby teeth. Exams every six months are recommended for the first several years, and annual checkups are usually adequate for mature horses unless the owner suspects there is a problem.
The vet or equine dentist first examines the outside of the cheeks and jaw for tenderness or bumps that can signal problems inside the mouth. A speculum is used to hold the jaws apart so the practitioner can look and feel for areas that need attention. A manual or electric rasp, known as a float, is used to smooth any rough or pointed edges. A water jet may be used to remove food material that has collected between the teeth, and broken or diseased teeth can be removed or repaired.
In past years, an equine dental exam consisted mostly of rounding off sharp edges and possibly removing dental caps or wolf teeth. Today new tools and techniques have expanded treatment beyond this simple beginning, and equine dentists routinely treat related problems such as gum disease.
Teeth that are slightly misaligned are not able to meet squarely, and the pressure of chewing can cause a tooth to rock slightly sideways as the horse chews. The sideways motion loosens the gum, allowing food particles to collect and decay. A pocket of infection forms, sometimes spreading to the connective tissue and bone surrounding the root. The result is often an abscess in the lower jaw or a sinus infection associated with the upper teeth.
Caught early, these infected areas can be flushed and then filled with polymer gels that contain a slow-release antibiotic. The gel keeps the gum pocket from refilling with feed, and the gum tightens as the infection heals. Eventually the gel is absorbed by the tissues, leaving a healthy gum.
Whom do I contact for equine dental care?
Your veterinarian is the first reference. Some veterinarians provide dental treatment in addition to their other services. Others prefer to supervise a professional equine dentist who has the specialized training, equipment, and experience to complete the work quickly and competently. In cases such as this, the supervising veterinarian can monitor the horse's reaction to dental procedures, administer tranquilizers, or prescribe antibiotics or other medications if they are needed.
How does a horse's dental condition relate to feed selection?
Healthy horses whose teeth are in good condition will have little trouble consuming almost any feed that is within their reach. On the other hand, eating is difficult for some horses, whether or not they have received regular dental care. In this category are very old horses or animals with malformed or damaged jaws or teeth. Owners of these horses may want to change both the type of feed and the form in which it is presented. Some options are switching from sweet feed to pelleted feed; providing fiber in the form of hay cubes instead of traditional hay; choosing a feed that includes beet pulp or soy hulls; and supplementing with fat (rice bran, corn oil) to add calories to the diet. Warm water can be added to pelleted or cubed feed to form a soft slurry for horses that cannot chew effectively. As with any feed change, make adjustments slowly over a period of several days.