This past weekend I power-floated a 22-year-old warmblood gelding and immediately noticed that he was “long in the tooth.” The term is widely used to describe something that is old, but did you know that long incisors in horses can be an indicator of a disease process? In other words - there are some cases in which long incisors occur due to something other than just aging. I am talking about Equine Odontoclastic Tooth Resporption and Hypercementosis or “EOTRH.”
EOTRH is characterized by disintegration of the incisor tooth roots and gingiva (gum) recession. In many cases, the surrounding gingiva will concurrently swell. The cause of this disease process is unknown, but it only occurs in aged horses (usually late teens onward). It can be painful, since loss of tooth roots can render the incisors unstable, thus causing nerve pain. In addition, as they loosen, food particles can pack down in between the tooth and the gingiva, resulting in infection and in some cases, tooth root abscesses. No fun.
Horses with EOTRH tend to not show many outward signs of tooth pain, but rest assured - they have it. Any of us who have ever had a tooth root abscess can attest! EOTRH horses may not be able to bite down on apples or carrots. They also sometimes exhibit signs of slow eating and reluctance to drink extremely cold water.
The first step in determining if a horse has EOTRH is to have a veterinarian do an oral examination of the incisors and canine teeth (these are the only teeth that are currently known to be affected by the condition). If the gingiva are receding and the teeth look “long” - there may be a problem. If the receded gingiva are swollen and there is excess cementum on the teeth - these also can be signs of the problem. Ultimately, taking intraoral radiographs of the incisors or canines can confirm the diagnosis. Radiographs will show black shadows around the roots of the teeth. In more advanced cases, the roots will literally be fractured off or missing altogether due to resorption.
Taking intraoral radiographs is not impossible to do with a conventional digital X-ray processor (termed a “DR” processor), however, there are special X-ray plates made specifically for evaluating incisors. Not all vets have them, but they are becoming increasingly more available as more and more veterinarians expand their dentistry services.
Your vet can get by with putting a normal digital radiograph plate in your horse’s mouth in order to assess the incisor teeth.
The best treatment for EOTRH is to extract affected teeth - especially if it is in an advanced state, if the horse is excessively painful, or if evidence of infection is present. Don’t worry though- horses can live and eat just fine without incisors. In fact, owners report that once painful teeth are removed, their horses act younger and more energetic. In cases where all incisors are removed, the tongue will hang out of the mouth. Other than looking a bit funny, it is of no detriment to the horse!
Want to read more dentistry by Dr. Miller? Here's an article explaining power floats and the need for regular dental care on your horse.