Dental Disease: EOTRH

Dr. Caity Cosentino

Horses can suffer from similar dental diseases that we do, but also have some disease processes that are specific to them. Equine Odontoclastic Tooth Resorption and Hypercementosis is one of those diseases. Often referred to as simply EOTRH, due to the fact that its full name is a mouthful, it is a disease that most regularly affects older horses age 15 years and up. It has been seen in horses in their earlier teens as well, but it is not as common. This is a progressive, painful disease. The disease process involves loss of bone and tissue (resorption) surrounding primarily the incisors (front teeth) and canines of patients. Due to the decreased integrity of the teeth, the affected teeth will be more prone to fracture and may loosen as well. Besides just the resorption, the condition can also be characterized by a proliferation of cementum, a calcified type of dental tissue, making a bulb-like appearance around the tooth roots. A close examination of the gums around the teeth may reveal red dots along the gum line, or even small draining tracts if the infection is also present. Sadly the cause of this disease is currently unknown.

It is sometimes hard for an owner to notice this problem, as there are not always drastic visible changes until later in the disease process. Horses may exhibit changes in eating and grazing, begin dunking hay or not wanting to bite treats, such as apples. They may be resistant to being bridled or shake their heads. Weight loss can be common, due to decreased food intake, because the condition is painful. A thorough veterinary exam should be done to rule EOTRH in or out as a differential diagnosis, along with other possible medical problems. Unfortunately, treatment for this disease is surgical extraction of the affected teeth. Radiographs are required to make a definitive diagnosis and determine which teeth are affected and to what extent they are affected. Lysis of the bone as well as enlargement of the roots will be visible on radiographs. The extractions can generally be performed on a horse who is standing, under sedation, and with the appropriate nerve blocks placed. Pain medication is provided during and after the procedure. An antimicrobial rinse is often provided as well. The recovery is fairly rapid in most patients and they can then return to eating and being ridden. Many horses actually have a better attitude and appear to be happier post-extraction, as they were experiencing some level of chronic pain with the condition. Even horses requiring extraction of all their incisors will happily return to grazing and being ridden once recovered. They will, however, have the tip on their tongue protruding from their mouth. Once the painful teeth are removed horses who have lost weight will often gain the weight back, and those that had resisted bridling often accept a bit without a fuss.

Annual dental exams are important for so many reasons. For the older horse, detection of EOTRH is important to help prevent pain associated with the disease, along with all the other problems that may come with it. Owners can help monitor their own horses between veterinary visits. Always be sure to look at your horses gums and incisors when bridling and note any changes over time. With many other dental concerns often happening with a horse’s premolars and molars, it can be easy to forget to check the front of your horse’s mouth as well.