The importance of the horse's mouth
- Jul 23
- 6 min read
The horse's mouth is clearly anatomy-adapted to a herbivorous diet and is the first compartment of the horse's digestive system, where food is prepared for its long journey through the digestive tract, hence the importance of the horse's mouth.
It provides four important functions: grasping food, chewing, salivation, and swallowing into the esophagus.
But the mouth is also an important means of communication for the horse to transmit signals to the outside world:
Horses often show their teeth to another horse as a threat, as if to say, "Be careful, I'll bite you."
Some horses bite their tongues, which exposes their teeth and can be an indication of discomfort.
They may also show their teeth to indicate pain. For example, by touching a sensitive spot while brushing, warning them that they'll bite if we continue touching that area.
Another mouth signal is the Flehmen reaction, which is a biological response to odor that helps activate an organ that allows horses to perceive chemicals in the air.
Foals and young horses sometimes extend their heads and necks, curl their lips back, and gently "click" their teeth to show subordination and avoid aggression from another member of the herd.
Licking and chewing without food in the mouth shows us release of tension and reduction of anxiety.
Finally, the mouth is also where we place the bit to communicate with the horse, exerting direct pressure on the mouth. This has an effect on the internal characteristics of the mouth, namely the bars, the palate, the tongue or lips, and the tissues that cover the bars of the horse's mouth in the corner area, which are precious to any rider. They must be treated with the utmost respect, as there is no second chance to create sensitivity once this area has been damaged during training.
To achieve smooth and flexible communication, we need the horse to have perfect oral health so that it accepts the bit in a relaxed and confident manner. We must bear in mind that each horse has individual preferences, a character and temperament of its own, which the bit combines with the rider's skills, so that cooperation is harmonious and with full acceptance of contact.
The horse is a selective eater. Its mobile, sensitive lips allow it to accurately select and grasp its food. The lips, like the eyes and nostrils, are equipped with long tactile hairs or whiskers known as vibrissae, which are essential for aiding in the perception and gathering of information about its environment. Depriving the horse of these sensory organs is considered detrimental to its well-being.
As we mentioned at the beginning, the digestive process begins when food enters the mouth. A horse's lips and teeth are adapted for grazing and browsing. The upper lip is strong, mobile, and sensitive and is used to place forage between the teeth, while the upper and lower incisors allow them to cut grass or foliage close to the ground.
The tongue pushes food toward the molars and premolars, where it is chewed. For the body to properly assimilate food, it must be properly ground before entering the digestive tract. For this reason, the horse has two powerful jaws adapted to its diet. The movable lower jaw makes circular movements against the fixed upper jaw for efficient grinding of food.
When food is chewed in the mouth, saliva is produced to aid in breakdown, swallowing, and buffering stomach acids.
Unlike many other animals, horses only produce saliva during chewing.
Horse saliva contains latherin, a protein that aids thermoregulation and may contribute to the digestion of coarse fibers. Latherin causes the production of a foam-like substance that forms during chewing and is generally considered a sign of good health in horses, although some may drool for other reasons, such as dental problems or stress, that may require attention.
The horse is a monogastric herbivore. Unlike ruminants (cows, goats, etc.), it cannot chew its food a second time, so it takes longer to chew. Ruminants do not chew much and first swallow grass or hay, which is fermented by bacteria in the rumen and breaks down the fiber. This process makes it easier to grind food into smaller particles during the second chew.
In its natural habitat, a horse spends 15 hours a day grazing, preferably on short, young grass, which is richer, and chewing every mouthful carefully. Highly adapted to this type of diet, the horse's teeth are composed of sharp incisors for slicing through the grass and well-developed (pre)molars for grinding food into smaller particles.
Horses have a psychological and physiological need to chew, which helps maintain their physical and mental well-being. A horse chews about 30,000 times a day, so it's essential that they do so without pain. We can also feed them from the ground, which is a natural position that promotes normal biomechanical function and sinus drainage.
Therefore, healthy teeth are necessary to promote efficient chewing, ensuring the reduction of fiber particles that can then be better broken down by digestive enzymes and bacteria.
Equines are brachydons (first premolars, wolf teeth, and canines) and hypsodonts (incisors and molars), meaning that horses have differently shaped teeth for different jobs and that they have two sets of teeth throughout their lives: baby teeth and permanent adult teeth.
By adulthood, around age 6, a horse will have between 36 and 44 teeth, including twelve incisors and a mix of molars and premolars; some horses, but not all, also have canines and wolf teeth.
Incisors and molars have a large body that continues to grow in the horse's mouth as it is worn down by fibrous feed material. Most of the tooth is below the gum line in younger horses and continues to develop as it enters the mouth. The roots of young teeth extend into the maxillary sinuses and mandibles, creating "tooth protrusions" in horses 2 to 5 years old.
Wear patterns caused by years of near-constant grazing, as well as tooth eruption, can be used as a rough guide to determining a horse's age.
Routine dental care is essential for a horse's health. Oral discomfort can lead to weight loss, decreased performance, and poor behavior.
That's why dentistry is an important part of a horse's overall health care. An annual oral exam is recommended to help monitor normal wear and tear and identify potential problems.
All teeth are made up of enamel, dentin, and cementum, but hypsodont teeth (incisors and molars) have several layers of these tough materials for high tensile strength and a durable grinding surface. Enamel is the hardest material in the body, but it is brittle. Therefore, it is supported by the surrounding dentin and cementum layers. As the tooth is ground down through chewing, the softer dentin and cementum are lost first, leaving the sharp enamel behind.
These sharp enamel points rub against the horse's cheeks and tongue while eating. Routine filing removes these uncomfortable points from the outside of the upper molars and the inside of the lower molars. Calluses and abrasions (ulcers) created by the sharp points heal quickly once the teeth are filed.
In addition to requiring routine care, other problems can arise from improper tooth development, eruption (growth), and wear. Improper development and eruption can lead to misalignment and reduce tooth longevity.
In summary, some common dental problems are:
Sharp enamel points and hooks on the cheek teeth, causing ulcerations and lacerations on the cheeks and tongue.
Excessively worn or abnormally long teeth
Retained crowns (baby teeth that do not fall out)
Fractured or displaced teeth
Decayed or infected teeth
Misalignment/poor position
Periodontal (gum) disease
We should therefore be alert to some common signs of dental disease, such as bad breath, excessive drooling, dropping partially chewed food, decreased appetite, difficulty eating, slow eating, poorly digested food in the manure, weight loss, behavioral problems when mounting, or nasal discharge from one side.
Just because a horse doesn't show obvious signs of dental disease doesn't mean everything is fine. In fact, only about 25% of horses with dental disease will show visible signs of dental disease. This is because horses, like most animals, simply adapt to their discomfort until the disease becomes a serious source of pain.
Dental disease can also affect the horse's overall health and lead to potentially fatal conditions such as colic and choking.
A complete dental exam, including viewing the premolars and molars, requires sedation, a speculum (mouth gag), and good lighting. Sedation helps keep the horse comfortable and safe while its mouth is examined. This is a standing sedation, meaning the horse will remain standing during the procedure.
Once sedated, a metal speculum is placed in your mouth to keep it open. After the exam, a motorized dental instrument (such as a file) with carbide blades is used to reduce sharp points, hooks, ridges, etc.
This procedure is not painful if performed correctly and usually takes 20 to 30 minutes, depending on the amount of work required. It typically takes another 20 to 30 minutes for the horse's sedation to wear off. Most horses can return to their normal routine the next day.
A horse's mouth changes constantly throughout its life and plays an important role in its overall health and happiness. With this in mind, we should ensure the horse's oral health and incorporate dental care into routine professional visits.
It's essential to keep your horse comfortable and help prevent dental problems. It will also help it use feed more efficiently, improving performance and even helping it live longer and with a better quality of life.
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