With increasing expertise focused on equine teeth, newly identified dental diseases are beginning to appear.

Equine odontoclastic tooth resorption and hypercementosis, more simply referred to as EOTRH, is probably the most important recently reported condition. The disease involves out-of-control growth of the “cementum”, or outer covering of the teeth, hence the “hypercementosis” part of the name. In addition, many horses suffer from destruction of the internal structure of the teeth (“resorption”).

EOTRH mostly affects the front teeth — the incisors and canines. It is usually found in horses above the age of 15, and some vets think it is more often seen in thoroughbreds and warmbloods.

Recent scientific publications debate whether the condition is infrequently found, or, in fact, under-diagnosed. It is important to know that it exists, because EOTRH can become a severe form of dental disease that creates irregular, misshapen front teeth with tender, receding gums.

Pain can manifest itself as a disinterest in food. Although some horses may show no obvious discomfort in the early stages of the disease, early warning signs include:

  • Evidence of a sore mouth with sensitivity to a bit being fitted
  • Increased salivation
  • Playing with water
  • Resistance to turning when exercised
  • Head-shy behaviour
  • Reluctance to grab feed with the affected front teeth.

Radical treatment

A careful examination is required to diagnose EOTRH, although some affected horses may resist pressure when their mouth is opened.

If you manipulate the mouth, especially the front teeth, or fit a gag (oral speculum) to look inside, it will hurt if the teeth are sore. There may be good reason why a horse does not want his mouth examined, and this needs to be checked, rather than simply assuming it is bad behaviour and reaching for a dose of sedation.

However, since it is not possible to ascertain exactly what is going on from the outside, X-rays are the only way of seeing the extent of the damage within the teeth.

EOTRH is progressive and, in time, all the front teeth will be affected. Unfortunately, there is no effective treatment other than the removal of diseased teeth — which sounds extreme, but a skilled surgeon can usually do this in the standing horse.

Horses with no incisor teeth can cope surprisingly well with appropriate dietary management post-extraction, including eating pelleted feed and hay products with reduced fibre length. Most horses can graze on longer new grass at pasture.

Nevertheless, in the absence of alternative treatment to tooth extraction, prevention of the disease is vital, and research is being carried out to identify EOTRH risk factors.

Overall, the key point is to be aware of this condition. If you are worried, ask an equine vet with an interest in dentistry to check the horse’s mouth.

Ref: Horse & Hound; 14 May 2015