Cover Story | Dentistry

Most Horses Less Painful, ‘Happier’ After Surgery for EOTRH

By Marie Rosenthal MS

Veterinarians can tell an owner whose horse has equine odontoclastic tooth resorption with hypercementosis (EOTRH) that the horse is experiencing pain, which is probably significant, but it is often hard for the owners to recognize the horse is painful, according to William Rainbow, DVM, an equine veterinarian, in Versailles, Ky.

Many owners are reluctant to remove all their horse’s incisors, which is the only treatment to eliminate the pain of EOTRH.

Dr. Rainbow surveyed owner satisfaction after the whole mouth incisor extraction to better arm veterinarians with information when they talk to owners. That survey found that once the procedure was done, most owners saw positive changes in their horse’s behavior—eating habits and body condition improved after incisor removal.

“After complete incisor removal of these horses with EOTRH we showed that horses had an improved body condition. They exhibited better bridling behaviors, they exhibited better eating behaviors, and owners felt that their horses were happier, and that the surgery had essentially improved the horses’ quality of life,” Dr. Rainbow explained at the 69th Annual Convention of the AAEP held in San Diego.

Progressive Dental Disease
EOTRH is a relatively recently described progressive dental disease that is poorly understood affecting primarily middle-aged and older horses. It is characterized by resorptive lesions in the teeth, which can cause teeth to become brittle and fracture easily, as well as hypercementosis.

“We know that it’s a progressive disease that generally starts with tooth resorption, but may also progress to hypercementosis. It generally starts on the corner incisors and progresses to the central incisors and sometimes the canine teeth as well. It’s oftentimes painful due to inflammation and periodontitis. We still don’t know a definitive cause or have a definitive cure that preserves the teeth either,” Dr. Rainbow said. However, the gingival inflammation and periodontitis readily resolve if the incisors are removed.

Veterinarians seem to be diagnosing EOTRH more, which makes sense because horses are living longer, he explained. Between 2003 to 2020, the number of horses being bred decreased by about 25%, but there are still many horses because they are living well into their 20s and older, according to Dr. Rainbow.

“Equine veterinarians report 12% to 40% of their patients are now older than 20 years old,” he said. In addition, the horse’s role has transitioned from being livestock or a commodity animal to a companion animal.

“The state of Kentucky did a survey 2 years ago, and they found 52,000 horses in Kentucky alone that were over 15 years old. That’s our prime EOTRH population,” Dr. Rainbow said.
In that same survey, horse owners said their biggest medical concerns for their horses centered around caring for their senior horses.

“Unfortunately, many owners view broken incisors, enlarged juga, and periodontitis as a normal age-related process, but they are not. However, many owners are really getting concerned about these old horses and wondering what they can do to care for them better, which I think is a pretty good,” he said.
Dental disease is an important issue for older horses that is under recognized and underdiagnosed, even though it’s staring everyone in the mouth, so to speak.
“We show up to do dental exams and show the horse’s mouth to the owner, and they go, ‘Wow, I’ve never seen that before.’ So, we know that it’s a surprising diagnosis for a lot of owners,” he said.

Making the Diagnosis
When a diagnosis of EOTRH is suspected, radiographs of upper, lower and canine teeth are obtained to confirm the condition. Once the diagnosis is confirmed, Dr. Rainbow educates owners about the progression of the disease and lets them decide if they would like to pursue surgical extractions to alleviate the symptoms.

Still, many owners are reluctant to remove all their horse’s incisors. They express concerns about how painful the surgery might be, recovery times, and how the horse will eat with all the incisors extracted.

“This is probably the most well-received surgery that we do for dentistry with people saying, ‘Thank goodness he did this. I got my old horse back. He acts younger, he’s gotten better.’ We had an idea that surgical extractions were effective for improving quality of life, but we didn’t really have a metric or a survey or anything to confirm it that maybe we could use to persuade more skeptical owners,” Dr. Rainbow explained.

Survey
In response, Dr. Rainbow’s survey might better arm veterinarians with information when they talk to owners about EOTRH surgery. He surveyed 48 horse owners who had elected to have all incisors extracted due to an EOTRH diagnosis. That survey found that once the procedure was done, most owners recognized positive changes in their horse’s behavior—eating habits and body condition improved after incisor removal.

Perhaps the most convincing component of the study was that 92% of owners strongly agreed that they would have the surgery performed if another of their horses developed EOTRH. This was consistent with what veterinarians have been seeing, but now had some statistical significance through a large survey.

“If we can get these owners to do this surgery, they’re going to be pleased with the results that they will see in their horse,” Dr. Rainbow said. MeV

For more information:
Rainbow W. Behavioral and physical changes in equine patients after complete extraction of all incisors due to equine odontoclastic tooth resorption with hypercementosis. Equine Vet Educ. 2024;36(5):240-244.
https://beva.onlinelibrary.wiley.com/doi/abs/10.1111/eve.13892