The horse evolved to eat large quantities of forage. In order to digest this fibrous foodstuff he must first crop the forage then grind it so that the nutrients become available to digestion and absorption. This requires eating about 16 hours a day. The forage often contains abrasive silicates. This places great demands on the teeth.

To compensate, the horse developed teeth with very long crowns, called hypsodont teeth. The long reserve of crown is embedded in the deep alveolus of the surrounding bone in the young horses' skull. Unlike humans, whose teeth are fully erupted at maturity, the equine's teeth slowly erupt over most of the horse's life at a rate of about 2 - 3 mm/year.

In the ideal world, this eruption rate just matches the wear rate and the rate sustains healthy teeth over the life of the horse. Domestication and the recent availability of inexpensive concentrates have changed this balance and to some degree the problems faced by horses today:

• The teeth do not wear down as fast resulting in the formation of sharp enamel points along the margins. Bridles, halters, and bits create areas where soft tissue is caught between the tack and the teeth.
• Uneven wear results in lost of alignment of the occlusal surfaces of the arcades of both the cheek teeth and incisors. Since the arcades do not mate well together it makes prehension and mastication less effective.
• Horses are living longer than they did in the wild. Often in the aged horse the teeth are wearing out, stop erupting, and eventually lost. At the same time the opposite tooth, no longer being worn down, overgrows it's arcade. Again, the problem of more difficult and less effective mastication occurs.

As you think about the above you realize that equine dentistry can be divided into three main activities:

1. Curing disease states of the mouth and teeth.
2. Improving the horses ability to prehend and masticate forage.
3. Improving the horses experience with tack and riding

No one would argue that removing damage or infected teeth is not good practise. Many horses, particularly older horses, suffer from dental disease. Clinical signs can range from mouth odor and pain to the point that it is functionally impossible for the horse to chew enough food to maintain weight.

Few would argue that correcting major arcade misaglignment is not good practise. These horses experience weight loss and difficult mastiction. Often this is observed as quidding where the horse stores chewed forage in the cheeks of his mouth. The thoughts are it helps soften the food and may even relieve pain by protecting the cheeks from the sharp edges of the mialigned teeth.

Their is a growing body of evidence that calls into question the frequent application of floating down the sharp edges that form along the cheek teeth margins. These sharp edges are called "cingulae". It has been widely thought this improves mastication and relieves discomfort during riding from the pressure of the tack on the cheeks. Some of these assumptions are being called into question by research.

In this article, we explain the anatomy of the horse's teeth in the foal and adult horse and we make recommendations for routine dental care based on your goals and the horse's endeavors while examining the controversial aspects of some procedures. Also discussed are common tooth problems addressed by dentistry and their treatment. More severe problems of the horse's mouth are covered at Disorders of the Horse's Mouth.

If you don't know someone with a horse that they have had for many years and have never had their teeth looked at and yet the horse is the picture of health, eats with gusto, and is great under saddle, you travel in a very limited crowd. In the excerpted summary results of a survey completed recently of horse management on Prince Edward Island, it was written:

..the horses were generally in good condition....Sixty-two horses had never had a veterinary dental examination...
Can Vet J. 2004 Dec;45(12):1004-11.
Demographics, management, and welfare of nonracing horses in Prince Edward Island.

Michigan State School of Veterinary Medicine recently was quoted as having said:

..in their herd of horses, regular dental exams were not done unless some clinical abnormality that could be related to the teeth occurred.

On the other side of this discussion are some of the equine dentists who are insisting that good care consists of exams every 6 months and floating about that often. They also recommend changing the general shape of the cheek teeth and removing some occlusal surfaces used for chewing. How can there be such a diversity of opinion? The diversity is because we do not have much hard data on these situations...yet. Just in the past ten years, this is starting to change. Two interesting studies showed:

• Horses who had teeth with significant points on the cheek teeth did not see an improvement in digestive efficiency when they were floated smoothly.
• Horses that received a "power float" with significant smoothing of the cheek teeth and loss of occlusal surface did not see a reduction in digestive efficiency.

It's a start but the results are sort of counterintuitive. Regular floating has been justified for these reasons:

• To improve mastication
• To head off long-term adverse changes in the teeth.
• Improve performance

The problem with chewing needs further study but some studies raise questions about this aspect of routine floating in an asymptomatic horse. The second point is valid, and there is no doubt that by making small adjustments all along some of the serious problems like steps, waves, hooks, and incisor misalignment can be prevented. It seems logical this may lead to longer tooth life as often the first teeth lost are those that receive excessive wear from uneven tooth growth but there are no studies to confirm or deny this.

The idea that even small points might cause resistance problems under saddle has recently been floated (eh hmmm..). It is common to observe lesions on the cheek caused by these points and the bridle exerts pressure against the cheek, forcing it onto the points. It seems logical that this might be painful to the horse. The problem is that horses with points rarely show visible problems associated with their tack. In one study there was a subjective opinion among experienced riders that while no problems were identified before the float, their horse's responsiveness was improved following floating.

I think that with what we know now that there is no single dentistry program that applies to everyone. You can decide the appropriate level of care by choosing what type of horse owner and what type of horse endeavors you are involved in. All horses, before they are bought, should have a good mouth exam. Assuming your horse does not have any tooth disease, abnormal wear patterns, or signs of mouth disease:

• Conservative: I don't ride my horses often or competitively. Though I do not want to neglect my horse due to time restrictions or expense, I need to do the minimum amount necessary to maintain good health.
  • Have the horse's teeth checked for three years or anytime there is a sign of mouth disease.
• Moderate: I like to trail ride whenever possible. Though I do not want to spend money unnecessarily, I want to ensure that my horse is given excellent care and is comfortable.
  • Have wolf teeth removed before training or if biting problems occur.
  • Have their horse checked yearly, and for routine care have points addressed, hooks, and plaque addressed.
• Aggressive: My horse must be at peak performance because I actively compete and winning is important. I do not care what it costs, I want to be sure my horse gets the best care.
  • Consider the moderate approach plus bit seats. There is no work or even logic that suggests more aggressive work is of benefit. We do not recommend aggressive powerfloating that removes significant portions of occlusal surface.

Anatomy, floating, and specific conditions are addressed below.