EORTH Syndrome

Equine Odontoclastic Tooth Resorption and Hypercementosis (EOTRH) is a painful dental disorder affecting the incisor and canine teeth, that is commonly seen in our older horses (>15yrs). This is a progressive disease that is, unfortunately often missed until extensive lesions are present.

EOTRH causes the roots of the affected teeth to start to resorb (dissolve), which is an inflammatory process. Concurrently, or possibly because of this, the tooth lays down extra cementum associated with the root of affect tooth/teeth. As the disease progresses, the teeth become loose and can fracture. Characteristics of EOTRH on visual exam include gingivitis (inflammation of the gum), gingival hyperplasia or recession, loose or fractured teeth. These teeth also commonly develop infections at the root, this can be identified as draining sinus/pimple like structures on gum line (see picture).

Horses are very stoic when it comes to oral pain. As such, clinic signs in horses affected by EOTRH range from asymptomatic, to weight loss, to signs of extreme oral pain (rubbing face, unwillingness to eat) and even colic. A common complaint is horses not biting down/taking treats such as apples and carrots as willingly as previously.

The etiology of EOTRH is not fully understood currently but similar disease processes are seen in both human and feline patients. Some suggested theories include an immune-mediated syndrome or increased occlusal forces or increased laxity in the periodontic ligament in aged teeth allowing bacterial infections.

Since EOTRH is a painful and progressive disease, it is important that a thorough examination is made of incisors and canine teeth during your horses’ routine dental examinations. If any changes consistent with EORTH are identified, intraoral radiographs should be recommended. There is currently no effective medical treatment and horses with clinical and radiographic signs should be considered candidates for extractions.

Owners often worry that old horses will have reduced quality of life with incisor removal but in fact the opposite is true. Horses’ quality of life improves drastically once the oral pain is removed. Horse often gain weight post extraction and seem more happy within.