Understanding EOTRH


In 2004, a new disease surfaced that threatens the dental health of primarily thoroughbreds and warmbloods. Equine odontoclastic tooth resorption and hypercementosis​ (EOTRH) is a painful condition that owners will want to keep an eye out for. Early detection of EOTRH increases the likelihood that the affected teeth can be removed safely before the condition advances very far. Therefore, any owner of a horse older than 15 will want to perform routine checks for EOTRH symptoms.

Risk factors of EOTRH
Ann Pearson MS, DVM​, recently led a group of researchers at Reata Equine Veterinary Group in Tucson, Arizona, through a study of the four main risk factors that increase the likelihood of a horse developing EOTRH. The results of the study indicated that the horses exposed to the following are at a greater risk of contracting the dental disease:

  1. Excessive dentistry: Horses that have undergone heavy dental procedures are at a greater risk due to a perceived connection between EOTRH and stress to the periodontal ligament.
  2. Periodontal disease/lack of grazing: Prior diagnosis of periodontal disease as well as a lack of grazing prevent saliva from efficiently cleansing the mouth. This is thought to contribute to EOTRH.
  3. Alfalfa hay diet: Feeding horses primarily alfalfa hay decreases saliva production due to the fact that such hay doesn't require much chewing. Allowing the horse to go out to pasture ensures that its head is in the downward position to allow saliva to coat the teeth inside the mouth.
  4. Endocrine disease: A history of endocrine disease may contribute to the development of EOTRH due to the resulting hormonal imbalances. Of special note is the effect of cortisol​, which is believed to have a negative effect on the periodontal ligaments.

What to look for
If your horse has been exposed to any of these risk factors, be sure to examine its teeth regularly for signs of lesions at the gumline. EOTRH causes the roots of the teeth to disintegrate, causing a build-up of cementum in response. The result is what looks like bulbous structures at the base of the teeth underneath the gums. In addition, small red spots may be visible on the gums in some instances of the disease. If you believe your horse is suffering from EOTRH, be sure to contact your veterinarian immediately. If left untreated, the teeth will eventually fall out and expose your horse's gums to the possibility of infection.