EORTH an Important Dental Condition in Aged Horses

Many horse owners rarely consider the health of their horses’ teeth outside annual or semiannual dental flotations. Because horses have continually erupting teeth, we might think horses shouldn’t be prone to permanent damage. Horses, however, can have many problems associated with their teeth, including a relatively newly recognized condition called EOTRH—equine odontoclastic tooth resorption and hypercementosis.

As described in a recent study published by veterinarians from the University of Helsinki’s Faculty of Veterinary Medicine, in Finland, EOTRH occurs in older horses—those at least 15 years of age. The condition develops when one or more teeth are resorbed and the body produces excess cementum—the hard, outer layer of the tooth—that replaces the bulk of the normal, healthy tooth. This condition typically starts at the outer incisors—the 12 small grasping teeth located at the front of the horse’s mouth. EOTRH then progressively moves toward the middle incisors, ultimately affecting all 12 incisors in some cases. The canines and cheek teeth can also be affected.

EOTRH can cause a great deal of discomfort. Affected horses have difficulties grasping and biting with their front teeth, impaired swallowing, decreased appetites, weight loss, and behavior changes (e.g., irritability).

“EOTRH has commonly been reported to be asymptomatic (having no clinical signs) at the time of diagnosis despite advanced dental lesions,” wrote the Finnish veterinarians.

They went on to state, “As the disease progresses, it is characterized by gingivitis, gingival edema and recession, associated periodontal disease, fistula formation, tooth mobility and displacement, tooth fracture and/or tooth loss.”

In other words, not only are the teeth diseased but also the tissues and bone supporting those teeth.

Taking X rays of a horse’s mouth can both diagnose the condition and allow veterinarians to determine the extent of the disease and decide how best to treat. Currently, removing the affected teeth is the only known treatment for EOTRH.

“Other treatments, such as systemic antibiotics, anti-inflammatories, and oral flushes have been used to reduce periodontal disease, but at best they offer only transient relief of symptoms,” said the research team.

While incisor extraction might seem radical to some owners, lead researcher Vahideh Rahmani and colleagues advised that removing the teeth will eliminate the source of pain and greatly increase the horse’s overall quality of life.

The study, “History, clinical findings and outcome of horses with radiographical signs of equine odontoclastic tooth resorption and hypercementosis” was published in Veterinary Record (volume 185). The full-length version is available here.