Equine odontoclastic tooth resorption and hypercementosis (EOTRH) is a dental disease characterized by tooth resorption (loss of dental tissue) and hypercementosis (overgrowth of dental tissue). In some cases, the surrounding bone may be destroyed (lysis). EOTRH can affect all teeth (incisors, canines, premolars and molars). The condition causes pain, with affected horses exhibiting noticeable signs, such as difficulty eating or refusing to be haltered or bridled.

EOTRH was first identified in 2004, and it typically affects horses over the age of 15. The disease is progressive, so the effects cannot be reversed. But with proper monitoring and treatment, affected horses can continue to live active, healthy lives.

Causes of EOTRH

The cause of EOTRH is unknown. While geldings seem more predisposed to the disease, there are several factors that may contribute to EOTRH, including:

• past overly aggressive dental procedures by improperly trained individuals,
• bacterial infection, 
• endocrine disease, 
• genetics, 
• horses who are not allowed to graze (i.e., kept on a drylot),
• interaction of autoimmune response, 
• masticatory (chewing) forces, and/or
• the presence of certain types of bacteria or other microorganisms in the mouth.

Another theory suggests that the increasing angulation of the incisors as horses age negatively affects the periodontal ligament that holds the teeth in place. The strained ligament causes chronic inflammation in the gums, which may affect the teeth. 

Signs

In the initial stages of EOTRH, there may be no visible signs. Over time, redness, swelling and recession develop in the gums of the affected teeth. Then, gingival ulcerations, heavy plaque and fistulae (draining tracts) with discharge may be observed. As EOTRH progresses, the teeth may loosen or fracture. Some teeth may develop a rough, bulbous appearance. Other signs may include:

• bad breath,
• head shyness or head shaking,
• refusing to be haltered or bridled,
• difficulty grazing, 
• reluctance to bite into apples
  or carrots,
• decreased appetite,
• weight loss, and/or
• irritation to tapping or manipulation of the incisors.

Diagnosis

If you see signs of infection or suspect that your horse has EOTRH, call your veterinarian to perform a complete sedated oral examination. She will look for fractured or loose teeth, pustules or draining tracts around the teeth, receding and/or swollen gums. In addition, dental radiographs must be taken to determine the location and severity of the condition below the gumline. 

Treating EOTRH

Regular oral and radiographic examinations can help monitor EOTRH in its early stages. As it progresses, the only treatment is to extract the affected teeth. Your vet will determine when or if extraction is needed based on clinical signs as well as examination and radiographic findings. Teeth will need to be extracted if they have deep pockets or severely receded gums around them, pustules or draining tracts, radiographs showing resorption into the sensitive dental tissue and/or are fractured or loose. 

Your vet may opt to remove only a few teeth at a time using regional and local anesthesia. However, in severe cases, a horse may need to have all incisors extracted at once, usually with standing sedation and regional nerve blocks. General anesthesia is rarely required.

After surgery, if the extraction sites are left open, gentle lavage with saline may be needed. If the sites are sutured, no flushing is required. Antibiotics are often prescribed as well as oral nonsteroidal anti-inflammatory medications. Most horses experience immediate relief after the extraction of the painful teeth, and their appetites and demeanor improve quickly. But they should not be ridden with a bit until the extraction sites are fully healed.

Horses generally cope well without incisors and quickly learn to use their tongue, gums and lips to pick up feed and grass. However, modifying their diets to include softer senior feeds may be necessary. Horses’ tongues may protrude from their mouths at rest or at work once their incisors have been removed.

Prevention

Since the cause of EOTRH is not understood, prevention of the disease is challenging and speculative. Work with your vet to perform regular oral examinations. Aggressive dental floating may accelerate the disease process. Good horse management to address issues, such as bacterial infection and endocrine disease, in a timely manner is important to a horse’s overall health and may be beneficial to slow the development of EOTRH. Also, one theory suggests that horses grazing daily with their heads down for many hours may protect their teeth by constantly bathing them with saliva. While more research is needed, ample grazing time may help prevent EOTRH. 

For more on equine dental care and common issues, click here.

Practical Horseman thanks Edward T. Earley, DVM, Dipl. AVDC-Eq, Dipl. AVDC-NSS/SA, for his technical assistance in the preparation of this article. Earley is the Associate Clinical Professor, Dentistry and Oral Surgery, at Cornell University College of Veterinary Medicine in Ithaca, New York. His clinical interests include tooth resorption, surgical extraction techniques, and sinus disease associated with dental diseases.

This article originally appeared in the Spring 2025 issue of Practical Horseman.

EVENTS

• WEF 9: March 4 – 9; Wellington, Florida
• Winter Spectacular X: March 4 – 9; Ocala, Florida
• TerraNova Winter Series IV: March 4 – 9; Myakka City, Florida
• World Equestrian Center March Dressage: March 5 – 9; Ocala, Florida
• Global Dressage Festival 9: March 6 – 9; Wellington, Florida
• Pacific Coast Dressage at Galway Downs: March 7 – 9; Temecula, California
• WEF 10: March 11 – 16; Wellington, Florida
• Global Dressage Festival 10: March 11 – 16; Wellington, Florida
• WEF 11: March 18 – 23; Ocala, Florida
• The Event at TerraNova: March 27 – 30; Myakka City, Florida
• Galway Downs International Horse Trials: March 27 – 30; Temecula, California

Watch & Learn on E+

Livestream: We’re super excited to announce that we’ll be livestreaming our first Galway Downs International Horse Trials in Temecula, California, on March 27 – 30. Watch on EQUESTRIAN+.

Gymnastics for Form: In this new video series on E+, Olympic show jumper Margie Engle explains how to teach your horse to develop form over fences and demonstrates flatwork and gymnastic exercises, including raised cavalletti, bounces and an in-and-out combination with a vertical and oxer. Check out her new series here.

Lateral Work, Changes & Trot Lengthenings: Dressage phenom Anna Buffini demonstrates how lateral movements build upon one another throughout a horse’s development and how to develop flying changes and trot lengthenings through the levels. Check out her new video series on EQUESTRIAN+ here.

Spring Health Checks

• Carefully check your horse’s pasterns for scratches.
• Inspect his hooves for thrush and/or soggy, weak hoof walls. For more on how to treat and manage thrush, click here.
• Get a Coggins test if your horse will be traveling this spring and summer.
• Do a fecal egg count test and deworm based on your horse’s living situation and your veterinarian’s recommendations.
• If your horse has had little to no access to quality pasture over the winter, consider checking with your vet to determine if you should have her vitamin E serum values checked.
• Schedule a dental exam and have your horse’s teeth floated if necessary.
• Work with your veterinarian to determine if your horse is due for any springtime vaccinations.
• As your horse is exposed to more light with the longer days and his winter coat starts shedding out, accelerate the process by using a shedding blade over the large areas of his body. Follow up with a stiff body brush to remove loose hair, dirt and dead skin cells to allow his sleeker, summer coat to grow in.
• Schedule a farrier appointment ahead of show season.
• Have your horse’s blood selenium levels check if you live in a selenium-deficient area.
• If your mare tends to get less-than-desirable to ride when she’s in heat and you use supplements, herbs or hormones to help manage her unwanted behaviors, check with your vet to see if now is the right time to start.

Barn & Trailer Management

• Check fence lines: Winter weather can be hard on fences. Examine your fences and enclosures carefully and make any necessary repairs.
• Clean out water troughs: Especially if your troughs have been partially frozen throughout the winter, give them a thorough cleaning.
• Trailer tune-up: This is good to do any time of year, but especially if your trailer has been sitting around for a few months, be sure to check the hitch, wheel bearings, tire pressure, lights, brakes, flooring and all latches.
• Start fly control: If you use a fly-control system like Fly Predators®, it might be time to deploy them depending on what part of the country you live in.
• Mud management: Use footing material like gravel or wood chips in areas heavily trafficked, manage manure, install gutters and downspouts, intercept surface flows and plant trees and shrubs to prevent your barn and surrounding areas from becoming a muddy mess as the last winter snow thaws.
• Spring cleaning: Power-wash stalls, scrub feed buckets, clear cobwebs, unclog gutters, declutter your medicine cabinet, organize your tack trunk, freshen up community areas and plant flowers to add a pop of color to your barn this spring.

Training & Show Prep

• Get the fresh out: Especially if your horse has been cooped up for much of the winter, help him get excessive energy out and ramp up his fitness with longeing sessions.
• Ready, set, check: Start your horse-show checklist to get all of your tack, apparel, equipment and other gear organized and ready for the competition season. Throw old or empty supplies out (or recycle) and replace as needed.
• Last call: Ensure all elements of your show apparel are clean, in good repair and working properly (if you wear a safety vest, for example). The same applies to your horse’s tack and other gear.

Baby On the Way?

• Prepare a foaling stall: Ideally, set up your mom-to-be’s foaling stall in a quiet location away from other horses and barn traffic. It should be roomy and open and free of any objects or protrusions that could pose a safety risk; be sure to provide safe water sources, non-stick bedding, fresh air and climate control for heat or cold. Washable walls and flooring will also make your life easier. Move your mare there well before her due date so she can get accustomed to her new quarters. For our full pre-foaling checklist, click here.
• Assemble a foaling kit: Key items include a halter and lead for your mare, headlamp with fresh batteries, stopwatch, notepad and pen (or your phone) to keep track of noteworthy events, tail wrap for your mare, small hand towels, large towels for drying the foal, bulb syringe, trash bags and disinfectant. Also, make sure you have your vet’s number programmed into your phone.
• Set up a foaling web cam: As your mare’s due date approaches, install a foaling webcam so you can easily keep an eye on her from anywhere and ensure it’s working properly well before the big day gets close.

Happy March, from your friends at Practical Horseman!

Does your horse do any of the following?

• Have trouble holding his head straight when ridden
• Have difficulty bending to the left or right
• Chew on the bit or excessively or turn his head when consuming grain
• Eat slowly or drop a lot of hay out of his mouth when eating
• Act head shy or resist when receiving oral deworming paste

These and many other behaviors could be signs that your horse is in need of dental care from a qualified and experienced professional.

As an equine veterinarian who focuses only on dentistry, I have found there is a lot more to dentistry than just grinding off the sharp enamel points. In this article, I will describe the common problems that many horses develop within their mouths and how these issues affect their ability to chew and to remain comfortable while being ridden. Proper care can improve their quality of life and extend the lifespan of their teeth. The underlying causes of many of the conditions discussed are complex and, in some cases, still not completely understood by the veterinary community, although we’re hoping that ongoing research will shed some light on the issues.

Anatomy Review

To have a better idea of the types of dental problems that can arise, it’s helpful to have a basic knowledge of the anatomy of the horse’s mouth. An adult horse can have as many as 44 teeth, depending on the individual. Males typically have only 40, while females generally have only 36 because they tend not to develop the four large canine teeth that the bit rests near.

Horses have 12 incisor teeth—six upper and six lower—which are used primarily to grasp forage and grain, transferring them to the tongue and then onto the cheek teeth. There are a total of 24 cheek teeth, with six upper teeth and six lower teeth on each side of the head, whose main function is chewing. The cheek teeth consist of three premolars and three molars in each row, also called an arcade. The most efficient chewing motion for the horse that will promote balance, comfort and appropriate wearing of the teeth is a side-to-side motion with both the left and right sides of the mouth being used equally. Horses are able to chew on only one side of their mouth at a time. When horses chew on the left side of their mouth, for example, the cheek teeth on the right are quite far from touching. Over the first 20–30 years of a horse’s life, his incisors and cheek teeth are almost always continuously erupting and grinding against one another.

Sharp Enamel Points

The most commonly addressed issue in a horse’s mouth is sharp enamel points on the premolars and molars. On the upper teeth, they are located on the side of the teeth nearest the cheek and on the lower teeth, they’re on the side of the teeth nearest the tongue. When sharp enough, these points can result in trauma to the tissues of the mouth, commonly called ulceration. The process of floating teeth is the act of using a grinding tool to smooth off these points. In my experience, horses tend to demonstrate specific behaviors while chewing and being ridden when they have these sharp points, such as:

• Turning their heads sideways or opening and stretching their mouths when eating
• Demonstrating some degree of resistance to the bit, especially with a tight noseband
• Flipping their heads or excessively chewing on the bit

Effects of Imbalance

Although sharp enamel points are usually the most common issue horse owners are concerned about, they are not the most important aspect of equine dentistry. The chewing surface of the cheek teeth of horses should be balanced so they are relatively level from the first tooth in the row to the last. This allows the arcades of the cheek teeth to function properly, lets the horse chew comfortably and efficiently and promotes appropriate wearing of the teeth. Imbalance, or the loss of that level surface, of the arcades of cheek teeth usually results from a number of abnormalities.

Abnormally formed teeth, misaligned teeth and many other issues will dictate how the upper and lower teeth grind upon each other, potentially resulting in overgrown areas along the rows of cheek teeth. These overgrown areas, commonly referred to as ridges, ramps, hooks, waves or steps (depending on the location and type of issue), can restrict chewing motion, develop gaps between teeth with feed-packing and cause fractured teeth, prematurely worn teeth and many other health and comfort risks. A small imbalance on the cheek teeth can turn into a significant issue within just a few months, especially in a younger horse. This is one of the main reasons that a yearly or biannually dental examination with attention to the causes of these imbalances is so vital.

Types of Imbalance

There are many types of damaging imbalances that can occur in a horse’s mouth, most of which result from overgrown areas due to an issue that can be corrected by timely, appropriate dental care.

• Hook: An overgrown area on the first cheek tooth.
• Ramp: If a horse tends to develop a hook, this usually indicates a type of alignment of the teeth that will result in a ramp in the opposite arcade on that same side. A ramp is an overgrown tooth at the back of the mouth that restricts the horse’s ability to chew side to side, resulting in an abnormal open-mouth chewing motion. Owners will often see their horse drop large amounts of feed when this is the case. A quick look in the horse’s mouth usually does not allow the practitioner to see all the way to the last tooth to identify any ramp overgrowth; a sedated exam with equipment to hold the horse’s mouth open is required to assess the degree of overgrowth.
• Waves and Steps: A wave is described as an overgrown area spanning multiple teeth, opposed by overworn teeth. This usually occurs toward the middle of the row of teeth (arcade). A step is similar to a wave, except the overgrown area is limited to a single tooth. Both of these types of imbalance can also restrict chewing motion and can lead to health issues as described below.
• Incisor Overbite/Underbite in Incisors: Horses also are prone to developing an overbite and, less commonly, an underbite on their incisors, which can sometimes lead to restricted chewing motion.

A horse may also have a restricted chewing motion if there is a painful area within his mouth or head or if there is a congenital defect or neurological issue. In my experience, the most common balance issue that causes restricted chewing is the presence of a ramp at the back of the mouth.

There is clinical evidence that restricted chewing motion or chewing on only one side of the mouth on a consistent basis will result in asymmetric chewing muscles on the outside of the horse’s head as well as a potential for pain around the temporomandibular joint (behind the eye and below the ear, where the lower jaw connects to the skull, see diagram above), although the latter has not been proven scientifically. In my experience, horses with restricted chewing motion usually have a resistance to bending or picking up a specific lead when being ridden. I have found that many of these horses receive regular chiropractic, massage or acupuncture treatments, but few show full benefit from these treatments until their mouths are properly addressed.

When a horse is presented for dental examination, causes of imbalance must be identified and any overgrown teeth should be reduced appropriately, even if he lacks sufficient sharp enamel points to consider him due for floating.

Dangers of Imbalance and Gingivitis

If imbalance advances far enough so that feed gets packed between teeth, then gingivitis, or inflammation of the gums, can set in. Gingivitis usually becomes chronic as the feed material is degraded by bacteria. The gingiva—gum—will lose some of its attachment to the tooth, which usually results in an even deeper space for feed material to become trapped in. Eventually, this can break down the periodontal ligament holding the tooth in place, loosening the tooth. This process is quite painful and can be the reason many horses are head shy or react to oral examination and floating, even with adequate sedation. If specific upper teeth develop infection around the roots, the potential for sinus infection can also exist.

Horses can experience feed-packing with associated gingivitis between the incisors as well. Ramps and hooks can also lead to feed-packing. As the overgrown last lower tooth presses against the last upper tooth, over time the lower tooth will be pushed from the front, so that it rocks backward. This chronic stress can be likened to braces on a person’s teeth. Eventually the lower tooth will shift, opening a gap for feed material to become chronically entrapped in. The same process also can occur when a horse’s hooks are left unaddressed. Once a space forms for feed material to become lodged in, this usually results in a chronic, painful issue for the horse if left untreated.

Usually canine teeth accumulate tartar, which should be cleaned by your veterinary dentist to reduce the possibility of gingivitis developing in that area.

Importance of Routine Care

Since the horse’s teeth are not readily visible, unlike lameness, injury or overgrown hooves, they can be forgotten. Most owners are not aware of the abnormalities present in their horse’s mouth and thus, these issues may not be addressed in a timely fashion. In fact, it seems many calls that I receive are for horses who have not been floated in years and are having difficulty eating, are dropping feed or having problems with the bit when ridden. In most of these cases, the problems are beyond repairing in one session or may even be so severe that fixing these issues is not possible.

An excellent way to give your horse the best opportunity for a comfortable, efficient set of teeth is to have them properly examined at an appropriate interval. My recommendation is as follows:

• Begin floating horses when they are 2 years old with biannual examinations with floating until age 5 (when all adult teeth should be fully in place).
• Horses 5 years old until roughly 7–8 years of age ought to be examined every nine months.
• Horses roughly 8 years old to geriatric age (around 20 years old) are seen once yearly
• Horses of geriatric age are generally seen twice yearly

If horses in any of these age groups are known to have dental abnormalities, they should be seen at least twice yearly to attempt to manage or correct any issues.

Erupting versus Growing

In the world of equine dentistry, the term “erupting” is different than “growing.” By the time a horse is 2–4 years old, his teeth are at the maximum length, but they have a very long root. Throughout the horse’s lifetime, the teeth are constantly being pushed into the horse’s mouth from the root area at the same time they are being worn down. This is why older horses have shorter roots and tend to lose more teeth.

Canine teeth are the single, large teeth that are located between the incisors and cheek teeth. Shortening them is not recommended because of their increased risk of fracture and the likelihood of damaging their internal structures.

Wolf teeth, if present, are located in front of the first cheek tooth. Some horses do not develop wolf teeth, but if they do, they can fall out on their own or are generally removed at a young age, as they can be a cause of discomfort when the horse is bridled. This is usually a result of their sharp tip and their small roots, which allow the tooth to wiggle when pressure is applied. Care should be taken not to fracture the root when this tooth is extracted; specialized tools are available to help your veterinary dentist accomplish this.

Criteria For Choosing An Equine Dentistry Professional

• The person should always perform a thorough head and oral examination under sedation using an oral speculum to keep the mouth open.
• He or she should prepare a detailed medical record describing any dental abnormalities.
• Any abnormal teeth or areas of teeth should be addressed (which may require X-rays or extraction of teeth).
• The mouth should be well balanced (without overaggressive reduction) and sharp enamel points should be rounded off.
• Incisor teeth require attention as well.
• Packed feed and tartar should be removed.

[PHOTOGALLERY uniquename=”galleria-azur”]

Photos ? Grady Kimbrell

Your horse abruptly stops eating. Maybe he starts quidding (dropping wads of partially chewed hay on the ground). He’s resistant when you bridle him or fussy while you ride. Or he yawns repeatedly, drools, bleeds or develops “bad” breath. Something must be going on in his mouth, but how do you check ? without losing a finger to those big and probably uncooperative teeth?

In this article I’ll demonstrate an efficient and thorough ?system that lets you assess almost everything oral from the outside of your horse’s lips to the rearmost premolar (you can’t see the molars without special dentistry equipment). I’ll also show you how to safely grab his tongue and pull it out of the way so you can see its underside as well as the roof?the palate?of his mouth.

It’s a simple and useful skill that just about any horse owner can master. In a few minutes, you will have enough information to decide whether you’re looking at a minor injury like a tiny cut that will heal on its own, a problem like a foxtail (a weed with a thorny seedhead) that you can quickly and easily remedy or a more serious situation like a deep cut or sharp hooks on the cheek teeth that need professional attention. Even if you can’t decide what you’re seeing, when you call your vet, you’ll have very specific information to convey.

A word of caution: Few horses like to have their mouths ?examined, but most will tolerate it with some degree of fussiness. If your horse looks as if he’s going to overreact and get ?violent, back off and call your vet. With a little sedation, he should be able to get the job done safely and thoroughly.

What You’ll Need

• A quiet, unlit stall or barn aisle away from distracting activity and where, when you look up into your horse’s mouth, you’re not squinting at the sun and so missing a lot of detail.
• A way to rinse your horse’s mouth so you can see more than chewed-up food?a gently-flowing hose works well if your horse will tolerate it, otherwise try a 60cc syringe of water. And if you have a choice, examine his mouth before feeding him.
• Something to illuminate the back of his mouth?a helper with a flashlight will do or you can wear an inexpensive headlamp such as I have, available through sporting goods stores or websites (type “headlamps” into your search engine).
• A loose-fitting halter so your horse can open his mouth without restriction.
• A lead rope. Cross-ties can be ?unsafe if your horse lunges forward, rears up or runs backward.

What will you look for? Be prepared! I once found a small piece of baling wire piercing a horse’s tongue and lacerating his palate every time he swallowed. But you’re far more likely to encounter
broken teeth.

• raw, dark-red ulcers, often from high doses of bute or irritating foreign bodies such as foxtails.
• cuts, which tend to be pink and deep. If a cut is minor?say your horse accidentally bit the edge of his tongue?it may bleed copiously for a while, but it should heal quickly and completely on its own. A laceration, any kind of gaping tissue or significant bleeding that won’t stop, is a vet call.
• calluses?greenish erosions with the raised surface of scar tissue??often caused by the continual ?rubbing of sharp, overlong teeth or hooks. inflamed gums with a raised, cauliflower-like appearance (gingivitis).
• fermented food in the spaces ?between the first three cheek teeth (premolars). This is probably the cause of any “off” odor you’re detecting.

Steve Goss, DVM, graduated from the University of California at Davis in 1988 and has practiced general veterinary medicine in Santa Barbara, California, since 1990. One-third of his practice is devoted to equine dentistry.

This article originally appeared in the February 2008 issue of Practical Horseman magazine.

Q. My lower-level dressage horse has a bad habit of grinding his teeth on the bit and making a noise. Judges have marked us down for this as being “tense.” My horse doesn’t seem tense to me and he does it all the time when I ride. Is there any way I can get him to stop?

Gerhard Politz

A. In dressage, we use the word “tension” to indicate a lack of relaxation and submission. Tension is not always manifested in obvious behavior problems such as spooking, bolting or coming above the bit. Sometimes it appears much more subtly. Particularly in stoic horses, teeth grinding or tail swishing may be the only perceptible response to an underlying physical discomfort. Unfortunately, if the discomfort is not addressed promptly, this response may turn into a habit, which can be difficult to eliminate. So the sooner you can identify the cause, the better.

Start your investigation in the most obvious place: your horse’s mouth. Ask a qualified equine dentist to perform a thorough mouth examination and teeth floating. (If your veterinarian has floated his teeth recently and noted no problems, it may still be worth getting a second opinion from a dental specialist.)

Next, enlist the help of an experienced rider or tack expert to evaluate the suitability and fit of your bit and noseband. To achieve proper acceptance of the bit, your horse must feel comfortable with the bit and free to move his jaw in a soft chewing motion. As this motion naturally generates a fair amount of saliva, visibly dry lips and mouth during your training session are also signs of bit/contact problems.

A too-thin bit or a bit adjusted too high in his mouth may discourage this chewing motion. Try lowering the bit a hole or two and experiment with different shapes and thicknesses of bits, as well as different types and combinations of metals, such as copper or sweet iron.

Also be sure your noseband isn’t so tight that it restricts jaw mobility. This is a common problem with flash and “crank” nosebands (the latter are aptly named and, unfortunately, often very detrimental to a horse’s proper acceptance of the bit). If you use one of these nosebands, consider switching to a dropped noseband, adjusted correctly along your horse’s chin groove. To be sure your noseband is adjusted loosely enough, you must be able to fit two or three fingers between the noseband and the nasal bone. Another simple method is to offer your horse a piece of carrot or apple when he’s bridled. If he can’t munch it easily, the noseband is too tight.

Find an expert to evaluate your saddle fit as well. It may be pinching your horse’s withers or pressing against his shoulder blades, which many horses find disconcerting, especially while trotting.

Ask your veterinarian to help rule out any other possible physical issues: sore back or hocks, sensitive soles, chiropractic problems (e.g., hips out of alignment), etc. What may not make your horse necessarily lame might be causing enough discomfort to manifest itself in teeth grinding.

At the same time, work with a qualified instructor to identify any rider errors that may be causing or contributing to the problem, especially in the way you use the contact to the bit. Rigid, bouncy or unsteady hands can cause a horse to go into “protective” mode. He may still perform all the movements asked of him but with a dry, immobile mouth and an inharmonious connection. I teach my students to influence their horses’ mouths in such a way that they are happy with the bit. With the correct, quiet elasticity and mobility in the connection, your hands create a conversation with your horse’s mouth. This skill takes years to master, but it should be made a top priority from the very beginning.

Finally, once you’ve investigated all of the above potential problems, consider your horse’s individual temperament. Perhaps he’s an overachiever who constantly tries to go more forward and do more work. With this type of horse, emphasize relaxation exercises, such as “chewing the reins out of the hands” and “releasing the reins with one or both hands.” Also encourage correct chewing motion by feeding him a sugar cube or two just before you mount. To break a long-standing teeth-grinding habit, it may even help to offer additional sugar cubes periodically during your ride.

Once you resolve the underlying cause–or combination of causes–of your horse’s tension, you will find that he not only stops grinding his teeth but also offers a happier connection and freer, more expressive movement throughout all of his work.

The career of Grand Prix dressage rider Gerhard Politz spans three countries and more than five decades. Before leaving his native Germany, he earned the professional Reitlehrer FN degree and the German Gold Medal for FEI wins while guiding several students to state and national championships. In England, he received certification as a British Horse Society Instructor. Since moving his program to Flintridge Riding Club in southern California in 1987, Gerhard has helped shape both the US Dressage Federation Instructor Certification Program and the design of the USDF dressage tests. His dedication to classical dressage principles and the training pyramid has benefited countless riders across the country, including many North American Junior and Young Rider Championships individual and team medalists.

This article was originally published in the January 2010 issue of Practical Horseman. Read more from Gerhard Politz in “Here’s How” in the May 2011 issue.