EOTRH in Horses: Signs, Diagnosis, and a Personal Perspective

I'm the proud owner of a 20-year-old Trakehner gelding named Pan.

Pan came into my life ten years ago through one of those rare, right-place-at-the-right-time moments—and soon became my dream dressage horse.

Level-headed, sensitive, and talented enough to compete at larger dressage shows, Pan and I built a successful partnership.

As an older horse, I knew some health concerns would eventually arise.

So when my equine dentist expressed concern during a routine exam this spring, I wasn't entirely surprised.

But what he found was completely unexpected.

"I think Pan may have EOTRH."

"Um…what?"
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Until that moment, I had never heard of EOTRH—a dental condition that primarily affects older horses.

What is EOTRH in Horses?

EOTRH (Equine Odontoclastic Tooth Resorption and Hypercementosis) is a progressive dental condition most commonly seen in older horses, typically those 15 years of age or older.

The exact cause of EOTRH is unknown, although some theories suggest a link to bacteria frequently found in the mouths of horses with EOTRH. Age and genetics may play a role, as the condition is common in older horses, particularly Warmbloods and Thoroughbreds.

In horses with EOTRH, the roots of the incisors—and sometimes the canine teeth—begin to dissolve in a process called resorption. As the roots weaken, the body produces cementum, a calcified tissue that tries to stabilize the tooth. This results in hypercementosis — an overproduction of this calcified tissue— often visible as bulbous swellings around the roots of the affected teeth.

As the condition worsens, the teeth become increasingly unstable. In more advanced cases, infections, abscesses, and tooth fractures occur.

These changes often develop gradually, making them easy to miss until the condition becomes more severe.

​Signs and Symptoms of EOTRH in Horses

Horses with EOTRH often show few obvious signs early on, making the condition easy to overlook. In my horse's case, nothing seemed unusual in his behavior.

As the disease progresses, however, noticeable signs can develop. One of the earliest is a reluctance to bite down on hard treats like carrots or apples.

Other signs may include:

• Resistance to the bit or bridle
• Irritability under saddle
• Dropping feed
• Reduced grazing
• Weight loss

By the time these symptoms appear, EOTRH in horses is often already advanced and causing discomfort.

This is part of what makes the condition so challenging to identify early—clinical signs tend to lag behind disease progression.
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For this reason, imaging plays a crucial role in early diagnosis.

​Diagnosing EOTRH in Horses

Because EOTRH in horses begins beneath the gumline and early clinical signs are minimal, it often goes unnoticed in its initial stages.
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As a result, EOTRH is often first identified during routine dental examinations. This is exactly how my horse's diagnosis unfolded this spring — the dental exam raised the concern; without it, I would not have recognized a problem.

During an oral examination, a veterinarian or equine dental practitioner looks closely at each tooth for subtle changes, such as tiny, pinprick-sized lesions along the gumline or the early signs of hypercementosis. While these findings may raise suspicion, they are not always definitive.

Dental radiographs are essential for confirming the diagnosis. They allow the practitioner to evaluate changes below the gum, including tooth root resorption, abnormal cementum deposits, and the extent of disease progression.

In many cases, radiographic changes are present before clinical signs develop.

​Treating EOTRH in Horses

EOTRH is a progressive condition that cannot be reversed, so treatment focuses on managing pain and improving quality of life. In most cases, the most effective approach is extraction of the affected teeth, either all at once or in stages.

A veterinarian typically performs the procedure under heavy standing sedation, using regional nerve blocks to keep the horse comfortable.

Post-operative care generally includes several days of pain management, and riding with a bit is usually restricted for about two weeks to allow the gums to heal.

Horses tend to respond very well to tooth extraction. During recovery—often four to six weeks—they can transition to soft feeds such as mashes before gradually returning to normal forage.

Many horses show a noticeable improvement in comfort and attitude once painful teeth are removed and can return to pasture grazing. Even without incisors, horses can grasp forage with their lips and tongue and keep chewing with their cheek teeth.

For horse owners, the idea of tooth extraction can sound extreme—but in the case of EOTRH, it is often the step that brings the greatest relief.

​My Experience with EOTRH

As expected with the progression of this disease, my horse, Pan, is scheduled for tooth extractions shortly.

Because his radiographs showed minimal to moderate resorption in most of his incisors, the current plan is to remove his two lower outer incisors.

EOTRH progresses differently in every horse, so I'm hopeful Pan's progression will be slow—but, as with many conditions like this, time will ultimately tell.

In the meantime, my equine dentist has recommended a proactive management plan, including biannual exams and annual radiographs, unless any behavioral changes suggest the need for earlier intervention.

What this experience has reinforced for me—both as a horse owner and as an animal health copywriter—is how quietly conditions like EOTRH can develop, and how important clear, early, informed communication can be.

Until this year, I had never heard of EOTRH. Now, I'm actively managing it with my horse. That shift—from unfamiliar term to real-world concern—is one I know many animal health companies are trying to bridge for their audiences every day.

And like many equine health conditions, the earlier those conversations start, the better the outcome—for both horses and the people who care for them.

Frequently Asked Questions About EOTRH in Horses

Here are answers to some common questions horse owners ask about EOTRH.
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What causes EOTRH in horses?
The exact cause is unknown, though bacteria, age, and genetics may play a role.

Is EOTRH painful for horses?
Yes—especially in advanced stages, when tooth instability and infection develop.

Can horses eat normally after tooth extraction?
Most horses adapt very well and return to normal grazing after recovery.

​Suzanne Quigley is an animal health copywriter specializing in long-form content for distributors, vendors, and pharmaceutical companies. Learn more about her work at Suzanne Quigley Copywriter.
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To discuss a project, contact her at [email protected] or call 508-277-4929.