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Teeth grinding in horses, also known as bruxism, is an abnormal behavior that often indicates pain, discomfort, or an underlying medical condition. The sound may be most noticeable while a horse is eating or resting, but horses may exhibit this clinical sign at any time.
Teeth grinding may be one of the first visible signs that a horse has an underlying health problem. Because many different disorders can produce the same behavior, identifying the cause is essential before treatment can begin.
Understanding when teeth grinding occurs, what other symptoms may be present, and which conditions are most commonly involved can help horse owners know when veterinary evaluation is needed.
Keep reading to learn what teeth grinding may mean in horses, how veterinarians diagnose the underlying cause, and what steps can help support your horse’s comfort and welfare.
Teeth Grinding (Bruxism) in Horses
Teeth grinding in horses, also called bruxism, refers to repetitive grinding, clenching, or gnashing of the teeth. [1][2] Although the behavior may occur intermittently, persistent teeth grinding in horses is generally considered abnormal and often indicates pain, discomfort, or an underlying medical condition. [1][2][3]
Teeth grinding may occur while eating, at rest, or during episodes of pain. The frequency and timing of the behavior can provide useful clues, but they are not enough to determine the diagnosis on their own. [1][2]
Bruxism is a symptom rather than a diagnosis. It is associated with disorders affecting the mouth, digestive tract, musculoskeletal system, and nervous system.
Although the exact mechanism is not fully understood, teeth grinding is thought to occur as a behavioral response to pain or discomfort, particularly when conditions affecting the mouth or digestive tract are present. [1][2][3][4][5]
Dental disease and equine gastric ulcer syndrome are among the most commonly recognized causes of teeth grinding in horses, although many painful conditions can produce similar behavior. [1][2][5][6]
Horses with gastric ulcers may exhibit bruxism alongside other behaviors associated with abdominal discomfort, while painful dental disorders can interfere with normal chewing and trigger teeth grinding. [5][6][7][8]
Since teeth grinding may indicate significant disease, persistent or unexplained bruxism should not be dismissed as a habit or behavioral quirk. Identifying and treating the underlying cause is the key to resolving the behavior. [1][2][3]
What's your top priority with your horse's health?
What's your top priority with your horse's health?
Is Teeth Grinding Normal in Horses?
Occasional jaw movement during normal chewing is expected, but repetitive teeth grinding is not considered normal behavior in horses. Persistent or exaggerated grinding usually indicates pain, discomfort, or another underlying health problem. [1][2][3]
The behavior may occur with dental disease, gastric ulcers, colic, musculoskeletal pain, neurologic disorders, or other painful conditions. [1][2][4][5]
Studies of horses with gastric ulcer syndrome have identified bruxism as a behavior associated with abdominal discomfort. Horses with more severe gastric ulceration may also show other pain-related behaviors. [5][8]
Because teeth grinding reflects discomfort rather than a specific disease, the behavior should be investigated, particularly if it persists or occurs alongside other symptoms such as reduced appetite, weight loss, quidding, colic, or behavior changes. [1][2][3]
What to Do If Your Horse Is Grinding Their Teeth
Owners should not ignore persistent teeth grinding, as it often indicates pain or another underlying medical problem.
Before contacting a veterinarian, owners can: [1][2][4][5][6][9]
- Record when the teeth grinding occurs, such as during eating, exercise, or resting
- Monitor for changes in facial expression or other signs of pain
- Check for changes in appetite or eating behavior
- Look for quidding, dropping feed, or difficulty chewing
- Monitor for colic symptoms or changes in manure
- Watch for additional behavior changes or signs of pain
- Review recent changes in diet, management, environment, or workload
- Avoid assuming the behavior is simply a habit
Regular observation of eating habits and behavior may help identify developing problems before persistent teeth grinding becomes established. Early intervention often improves outcomes for many painful conditions. [1][2][3]
Prompt diagnosis and treatment of the underlying cause offer the best chance of resolving teeth grinding and preventing further complications. [1][2]
When to Call the Veterinarian
Because teeth grinding can reflect several painful conditions, persistent or unexplained bruxism warrants veterinary evaluation. This is especially important when the behavior is new, increasing, or occurring with other signs of illness or discomfort.
Contact your veterinarian if teeth grinding occurs with:
- Reduced appetite, weight loss, or difficulty chewing
- Quidding, drooling, bad breath, or other signs of dental pain
- Colic signs, changes in manure, or repeated looking at the flank
- Poor performance, resistance under saddle, lameness, or stiffness
- Behavior changes, abnormal coordination, or unusual jaw movement
A veterinarian can evaluate whether the behavior is related to dental disease, gastrointestinal pain, musculoskeletal discomfort, neurologic disease, or another condition. Prompt assessment helps avoid delays in treating the underlying problem.
Common Causes of Teeth Grinding in Horses
Teeth grinding is commonly associated with pain or physical discomfort in horses. It is a symptom rather than a specific disease, and the horse’s behavior alone does not reveal where the pain originates. [1][3]
Grinding while eating may point toward an oral problem, while grinding accompanied by colic signs may indicate gastrointestinal pain. When the behavior appears during movement or ridden exercise, other painful conditions may also need to be considered. [1][2][3][4]
Dental Disease
Painful dental and oral disorders are important possible causes of teeth grinding in horses. Some conditions create direct tooth pain, while others injure the gums, cheeks, or tongue or make normal chewing uncomfortable. [2][6]
Potential causes include: [2][6]
- Sharp dental overgrowths that rub against or injure the cheeks and tongue
- Gaps between the teeth that trap food and contribute to painful periodontal disease
- Fractured, displaced, infected, or abnormally worn teeth
Grinding related to dental pain may become most noticeable while the horse is eating, chewing forage, or wearing a bit.
Other signs can include: [2][6]
- Changes in chewing
- Dropping partly chewed feed
- Reduced feed intake
- Bad breath
- Swelling around the jaw or face
With that being said, it’s important to note that horses can have significant dental disease without showing obvious symptoms. [2][6]
A complete oral examination is often necessary to identify the source of discomfort. Some abnormalities are located near the back of the mouth or below the gumline and cannot be detected by looking only at the front teeth. [2][6]
Gastric Ulcers
Equine gastric ulcer syndrome is another possible cause of teeth grinding in horses. Ulcers damage the lining of the stomach and may cause abdominal discomfort, particularly around feeding, exercise, or other situations that affect the stomach. [1][5]
Horses with gastric ulcers can show behavioral changes associated with discomfort, but these signs vary widely between horses. Some affected horses show few outward signs, while others may develop: [1][5][8]
- Reduced appetite
- Recurrent mild colic
- Poor performance
- Changes in attitude
- Bruxism
Research has found that horses with more severe gastric ulceration display more frequent behaviors associated with pain and stress. However, teeth grinding and other behaviors cannot confirm gastric ulcers on their own. Gastroscopy, which allows a veterinarian to examine the inside of the stomach, is required for a definitive diagnosis. [5][8]
Other Forms of Gastrointestinal Pain
Teeth grinding can occur with abdominal pain arising from other parts of the digestive tract. It may accompany gastrointestinal disorders that cause inflammation, stretching, blockage, or abnormal movement of the stomach or intestines. [1][4]
Because colic describes abdominal pain rather than one specific disease, the signs can vary depending on the underlying problem. A horse experiencing digestive pain may grind its teeth alongside reduced appetite, looking at the flank, pawing, restlessness, or repeated attempts to lie down. [1][4]
Neurologic Disorders
Neurologic disorders are a less common cause of teeth grinding than dental disease or gastrointestinal pain. However, conditions affecting the brain, brainstem, or nerves controlling the face and mouth can alter a horse’s behavior or interfere with normal jaw movement. [1][4]
When bruxism is related to neurologic disease, other symptoms are usually present. These may include: [1][4]
- Loss of coordination, stumbling, weakness, or an abnormal gait
- Changes in behavior, such as lethargy, confusion, circling, or unusual reactions to the surroundings
- Facial asymmetry, a drooping lip or ear, or difficulty controlling the tongue
- Tremors, seizures, or other unusual movements
- Difficulty chewing or swallowing, excessive drooling, or feed and water coming from the nostrils
These signs can occur when disease or injury affects the parts of the nervous system responsible for movement, sensation, swallowing, and normal behavior. Teeth grinding alone does not confirm a neurologic disorder, and veterinarians must interpret this sign alongside the horse’s complete pattern of symptoms. [1][3]
A veterinarian may recommend a neurologic exam, which assesses the horse’s awareness, facial movements, swallowing ability, posture, reflexes, gait, and coordination to determine whether the brain, spinal cord, or peripheral nerves are affected. [1]
Musculoskeletal Pain
Pain affecting the neck, back, limbs, joints, or supporting soft tissues may also contribute to bruxism. Horses do not always express pain in an obvious or consistent way, and chronic discomfort may first appear as a change in behavior, attitude, or performance. [1][3][4]
Musculoskeletal pain may be more likely when teeth grinding occurs during exercise and is accompanied by: [3][10]
- Stiffness, shortened strides, or another change in movement
- Reluctance to move forward or perform a particular exercise
- Resistance, changes in facial expression, or declining performance
Teeth grinding does not specifically indicate musculoskeletal pain, and veterinarians do not rely on this behavior alone to diagnose back pain or lameness. Veterinarians assess it alongside the horse’s gait, physical examination findings, medical history, and other behavioral signs. [3][9]
Other Painful Conditions
Bruxism may occur with painful illnesses or injuries that do not primarily affect the teeth, digestive tract, or musculoskeletal system. Horses recovering from surgery or experiencing severe inflammation, internal disease, or another source of ongoing pain may grind their teeth as part of a broader pain response. [1][3][4]
Other signs of pain may include: [1][3]
- Changes in posture
- Facial tension
- Reduced interaction with the surroundings
- Altered appetite
- Restlessness
- An unusual response to handling
Because individual horses express pain differently, veterinarians assess several physical and behavioral findings rather than relying on teeth grinding alone. [1][3]
Owners must not dismiss persistent bruxism as a habit or a result of stress until painful medical conditions have been investigated. Identifying and treating the underlying cause is necessary to resolve the discomfort and reduce the behavior. [1][3]
Table 1. Common causes of teeth grinding in horses
| Possible Cause | Common Clues | Why It Matters |
|---|---|---|
| Dental disease |
|
|
| Neurologic disorders |
|
|
| Gastric ulcers |
|
|
| Other gastrointestinal pain |
|
|
| Musculoskeletal pain |
|
|
| Other painful conditions |
|
|
These signs can overlap across several conditions, so the full pattern of symptoms is more useful than any single sign. Timing, severity, and recent changes in diet, workload, or behavior can help guide the veterinary examination.
Diagnosis & Treatment
Identifying the underlying cause of bruxism is the first step in treatment, because teeth grinding is a symptom rather than a disease. [1][2][4]
A veterinarian considers the horse’s history, eating behavior, signs of pain, oral health, and any additional symptoms to determine the most likely cause. Veterinarians may also need to assess gastrointestinal, musculoskeletal, neurologic, and dental health. [1][2][3][4]
Diagnostic tests may include: [1][2][4][5][6][7]
- Oral examination
- Sedated dental examination
- Blood tests
- Gastroscopy
- X-rays
- Ultrasound
- Endoscopy
- Advanced imaging
Since many conditions can produce similar signs, diagnosing the underlying cause may require several diagnostic tests. This helps ensure treatment is directed at the disease responsible for the behavior rather than the teeth grinding itself. [1][2][4]
Treatment
Treatment depends on the diagnosis and may include: [1][2][4][5][6][7]
- Dental treatment
- Pain-relieving medications
- Anti-inflammatory medications
- Medications for gastric ulcers
- Dietary management
- Surgery
- Supportive care
In many cases, teeth grinding improves once the underlying source of pain or discomfort has been successfully treated. [1][2][3]
Prevention
Not all cases of teeth grinding are preventable, but reducing the risk of painful medical conditions may help decrease its occurrence. [1][2][4]
Preventive measures include: [1][2][4][5][6]
- Schedule routine dental examinations and treatment, including teeth floating
- Provide a balanced diet with adequate forage
- Reduce the risk of gastric ulcers through appropriate feeding and management practices
- Monitor for changes in appetite, chewing, body condition, or behavior
- Address signs of pain promptly
- Maintain a consistent daily routine when possible
- Schedule routine veterinary care
Recording when the behavior occurs, such as during eating, exercise, or while resting, may help identify patterns that assist the veterinarian during the diagnostic process. Early recognition and treatment of underlying disease may prevent persistent teeth grinding and improve long-term health and welfare. [1][2][3]
Frequently Asked Questions
Here are some frequently asked questions about teeth grinding in horses:
Horses grind their teeth because they are often experiencing pain, discomfort, stress, or an underlying medical condition. Teeth grinding, also called bruxism, is a symptom rather than a disease itself. Common causes include dental disease, gastric ulcers, colic, musculoskeletal pain, neurologic disorders, and other painful conditions. Because many different problems can cause the same behavior, the timing of the grinding and any other symptoms help guide the next steps.
Teeth grinding is not considered normal in horses when it is repetitive, persistent, or exaggerated. Normal chewing involves jaw movement while eating, but bruxism may occur while eating, at rest, during exercise, or during episodes of pain. Ongoing grinding usually indicates discomfort or another health problem rather than a harmless habit. Persistent or unexplained grinding should be investigated instead of ignored.
Teeth grinding does not always prove that a horse is in pain, but persistent bruxism is commonly associated with discomfort or disease. Pain affecting the mouth, digestive tract, musculoskeletal system, or nervous system can all produce similar behavior. Stress or management changes may also be part of the picture, but painful medical causes should be ruled out first. Owners should avoid assuming the behavior is simply a habit until the horse has been properly evaluated.
Dental problems can cause teeth grinding in horses when painful oral conditions interfere with normal chewing. Sharp enamel points, fractured teeth, periodontal disease, gaps between teeth, tooth root infections, and abnormal wear can all make the mouth painful. Other signs may include quidding, dropping feed, drooling, bad breath, difficulty chewing, reduced appetite, weight loss, or swelling around the jaw or face. A complete oral examination is often needed because some dental problems are located near the back of the mouth or below the gumline.
Gastric ulcers can cause teeth grinding in horses because stomach discomfort may trigger pain-related behaviors. Horses with gastric ulcers may also show reduced appetite, recurrent mild colic, poor performance, attitude changes, or weight loss, but some horses show few obvious signs. Teeth grinding alone cannot confirm ulcers. Gastroscopy is required for a definitive diagnosis.
Colic can cause teeth grinding in horses when abdominal pain leads to visible discomfort behaviors. A horse with digestive pain may also paw, look at the flank, become restless, reduce feed intake, show changes in manure, or repeatedly try to lie down. New or persistent grinding with colic signs should be treated as a veterinary concern. Some gastrointestinal conditions can progress quickly, and the intensity of the grinding does not always reflect the seriousness of the problem.
A horse that grinds their teeth while eating may be experiencing oral pain, dental disease, or discomfort associated with chewing. Grinding during meals, while chewing forage, or while wearing a bit can point toward dental or mouth-related problems. Signs such as dropping feed, quidding, bad breath, reduced intake, or facial swelling make a dental cause more likely. However, eating-related discomfort can overlap with other conditions, so veterinary and dental evaluation may be needed.
A horse that grinds their teeth at rest may be showing discomfort that is not directly related to chewing. Gastric ulcers, other gastrointestinal pain, chronic musculoskeletal pain, neurologic disease, or another painful condition may contribute. Resting bruxism should be taken seriously if it is new, persistent, or occurs with appetite changes, colic signs, lethargy, behavior changes, or weight loss. Tracking when it happens can help your veterinarian narrow down possible causes.
A horse that grinds their teeth under saddle or during exercise may be reacting to pain, discomfort, or resistance associated with work. Musculoskeletal pain is more likely when grinding occurs with stiffness, shortened strides, reluctance to move forward, declining performance, facial tension, or lameness. Dental pain or bit discomfort may also contribute, especially if the horse resists contact or shows chewing abnormalities. Teeth grinding during work should be assessed in the context of tack fit, dental health, movement, workload, and the horse's full pain picture.
Other symptoms that can occur with teeth grinding in horses depend on the underlying cause. Possible signs include reduced appetite, quidding, weight loss, drooling, bad breath, difficulty chewing, colic symptoms, changes in manure, poor performance, head shaking, resistance to the bit, pawing, tail swishing, lameness, stiffness, or looking at the flank. Neurologic signs such as incoordination, facial asymmetry, drooling, abnormal gait, tremors, or difficulty swallowing are less common but important. These accompanying signs help a veterinarian decide which causes are most likely.
A veterinarian should be called for teeth grinding when the behavior is persistent, unexplained, worsening, or occurs with other signs of illness or pain. Warning signs include reduced appetite, weight loss, quidding, difficulty chewing, drooling, bad breath, colic symptoms, changes in manure, poor performance, lameness, stiffness, or notable behavior changes. Prompt veterinary assessment is especially important if the horse has severe colic signs, cannot eat, becomes markedly lethargic, or worsens quickly. Early evaluation helps prevent delays in treating the underlying problem.
Teeth grinding in horses is diagnosed by identifying the underlying cause of the behavior. A veterinarian may review the horse's history, eating habits, pain signs, oral health, workload, management changes, and any additional symptoms. Diagnostic testing may include an oral examination, sedated dental examination, blood tests, gastroscopy, X-rays, ultrasound, endoscopy, a neurologic exam, or advanced imaging. Because many conditions can produce similar signs, diagnosis may require more than one test.
Teeth grinding in horses cannot be diagnosed by sound or behavior alone because bruxism only shows that something may be wrong. The sound may be easy to recognize, but it does not reveal whether the source is dental, digestive, musculoskeletal, neurologic, or another painful condition. Timing can provide useful clues, such as grinding during eating, exercise, or rest. A full veterinary assessment is needed to determine the actual cause.
Teeth grinding in horses is treated by addressing the condition causing the pain or discomfort. Treatment may include dental care, pain-relieving medications, anti-inflammatory medications, medications for gastric ulcers, dietary management, treatment of gastrointestinal disease, surgery, or supportive care. The correct treatment depends on the diagnosis rather than the grinding itself. In many horses, bruxism improves once the underlying source of discomfort is successfully treated.
If your horse starts grinding their teeth, record when the behavior occurs and watch for other signs of pain or illness. Note whether the grinding happens during eating, exercise, rest, or around management changes, and check for appetite changes, quidding, manure changes, colic signs, performance changes, or abnormal behavior. Do not assume the behavior is harmless or purely stress-related. Contact your veterinarian if the grinding persists, worsens, or occurs with other concerning signs.
Teeth grinding in horses cannot always be prevented because many different painful conditions can cause it. However, routine dental care, balanced nutrition, adequate forage, consistent management, routine veterinary care, and early attention to signs of pain may reduce the risk. Reducing ulcer risk through appropriate feeding and management practices may also help some horses. Monitoring changes in appetite, chewing, body condition, performance, and behavior can help identify problems before grinding becomes persistent.
Summary
Teeth grinding in horses, or bruxism, is repetitive grinding, clenching, or gnashing of the teeth.
- Persistent teeth grinding is abnormal and often indicates pain or discomfort
- Common causes include dental disease, gastric ulcers, colic, musculoskeletal pain, neurologic disease, and stress
- Other signs may include reduced appetite, quidding, weight loss, drooling, colic signs, poor performance, or behavior changes
- Diagnosis focuses on finding the underlying cause through dental exams, gastroscopy, imaging, bloodwork, or other testing
- Veterinary evaluation is recommended for persistent, new, worsening, or unexplained teeth grinding
References
- Reed. S. M. et al. Equine Internal Medicine. 4th ed. Elsevier. 2018.
- Easley. J. et al. Equine Dentistry. Elsevier. 2011.
- Gleerup. K. B. and Lindegaard. C. Recognition and Quantification of Pain in Horses: A Tutorial Review. Equine Veterinary Education. 2016.
- Auer. J. A. et al. Equine Surgery. Fifth edition. Elsevier. 2019.
- Sykes. B. W. et al. European College of Equine Internal Medicine Consensus Statement—Equine Gastric Ulcer Syndrome in Adult Horses. Journal of Veterinary Internal Medicine. 2015. View Summary
- Dixon. P. M. and Dacre. I. A Review of Equine Dental Disorders. The Veterinary Journal. 2005. View Summary
- Lensing. R. et al. Association of Equine Squamous and Glandular Gastric Disease with Dental Status in 54 Horses. Animals. 2024. View Summary
- Perron. B. et al. The Influence of Severity of Gastric Ulceration on Horse Behavior and Heart Rate Variability. Journal of Veterinary Behavior. 2023.
- Gleerup. K. B. et al. An Equine Pain Face. Veterinary Anaesthesia and Analgesia. 2015. View Summary
- Dyson. S. et al. Development of an Ethogram for a Pain Scoring System in Ridden Horses and Its Application to Determine the Presence of Musculoskeletal Pain. Journal of Veterinary Behavior. 2018.
