An average horse has between 36 and 40 teeth, consisting of 12 incisors, 12 premolars and 12 molars. The extras are made up of canines or wolf teeth if present. Cheek teeth should be in a straight line and are supposed to have a rough surface. This allows for grinding of food.
Teeth are considered to grow until they come into wear, then erupt until they are worn down to the root. Teeth can last 20-30 years if looked after properly.
Horses jaws are uneven, with the top jaw being up to 30% wider than the bottom. The chewing surface of cheek teeth is tilted 12-15 degrees. This, combined with the circular chewing action of a horse can often result in dental problems without regular maintenance.
Let’s take a minute now to watch just how a horse chews.
So how do you know if your horse has dental disease?? Like I mentioned previously, the circular action of chewing combined with the unequally sized jaws mean that sharp points develop on the outside of the upper teeth and the inside of the lower cheek teeth. These sharp points cause pain in your horses mouth which often leads to problems with performance, particularly under saddle. Head shaking or tossing, poor response to pressure on the reins, lugging to one side or head tilting, rearing and bucking or working behind the bit are all signs your horse may have an uncomfortable mouth. Other behavioural problems when being ridden that may be secondary to mouth pain include poor or hard collection, refusal to maintain frame or vertical head carriage, refusal to take one lead or being slow in transitions, resistance to turning in one direction, pulling hard, refusing to accept bridling or rearing when bridled, getting the tongue over the bit or sticking the tongue out, slightly opening mouth when head in vertical position, chewing the bit (this may become a habit) and tail swishing.
The other thing that would obviously be affected by a sore mouth is eating. Spilling feed, excessive salivation, quidding and slow eating, frequent washing of mouth in water, aggression or anxiety during eating, eating hay but leaving grain or faeces with large numbers of long fibres or undigested grains are also all signs your horse may have dental disease.
The aim of dentistry is to maximise comfort when eating or being ridden. During routine dentistry the sharp enamel points are removed and the first cheek teeth contoured to create a bit seat.
The next question is, how often should I have my horses teeth looked at?? Many factors impact on the rate at which teeth wear. Diet places a big role. A horses natural diet is made up of grass, and this is what teeth are designed to chew. Rough pastures high in minerals like silicates cause the teeth to be worn away faster than if the horse was grazing lush green grass. This means that a grass diet sees the slowest return of sharp enamel points, followed by hay, then chaff, pellets and grain.
Younger horses also have teeth that wear away faster, meaning points return faster as well. So generally it is recommended that a young horse (one that is less than 8 or 9 years old) should have their teeth done every 6 to 9 months, particularly if they are not grazing continually, while an older horse should have their teeth done every year.
As many of you have seen, when we talk about having a horse’s teeth done, we are referring to the grinding or filing back of sharp points, hooks, waves, ramps or tall teeth usually using the power float. Horses are nearly always sedated in order to get the best result.
This is a picture of what a well maintained mouth should look like. See how all the teeth are in a straight line with no hooks waves or ramps and all the sharp enamel points have been filed away. The first cheek tooth is contoured to allow for the most comfortable bit position.
Many problems can occur with horses teeth. For ease of discussion I have categorised them into problems associated with young horses under 5 years old and those affecting adults.
One common problem seen in young horses is retained incisor or premolar caps where the deciduous teeth fail to fall out when the permanent teeth are ready to replace them. Impaction of erupting incisors can also be a problem. Eruption bumps or cysts can cause discomfort even if the teeth have been done regularly if the noseband of the halter or bridle is fitted incorrectly. Incompletely erupted or unerupted wolf teeth are also seen occasionally.
Older horses have problems with malocclusions where the teeth fail to come together as they should. Excessive tranverse ridges, hooks, ramps and tall molars can all be the result of malocclusions. Any condition that causes pain in the mouth and so changes the way a horse chews can result in abnormal wear on the teeth. This is often seen as wave or step mouth. Conditions causing pain in the mouth include fractured or chipped teeth, periodontal disease or gingivitis. Horses of any age can be affected by soft tissue injuries from sharp teeth.
Now let’s discuss some of the more common myths associated with equine dentistry. The first myth is that sedation is only for badly behaved horses or practitioners who can’t handle horses. Sedation allows for a thorough examination involving touch and sight. This helps identify any problems early for easiest treatment and management. Sedation also allows for equipment such as light and mirrors to be used, and reduces stress on the animal. Another thing to consider is that the worse the pathology in the mouth the worse the unsedated horse plays up, and he is the one that needs a thorough job the most. Only vets can legally sedate a horse and have the insurance to do so.
The second myth is that dentistry is expensive. At around $2.50 per week it is a small price to pay for your horses well being. Compare this to average costs for feed and hoof care. Regular dental care can help prevent many cases or colic or choke and a happy horse usually means a happy rider.
Myth three. Dentistry is just about teeth. Dentistry is about total mouth care. Gum and periodontal disease is painful and is one of the most common conditions affecting mammals, including horses. Tumours, infections, feed impactions and foreign bodies are found regularly during proper dental examinations.
Myth four and five are two sides of the same coin. A thin horse does not necessarily have bad teeth and a fat horse does not necessarily have good teeth.
The second last myth is that power tools are dangerous. The response to this is that yes they can be in the wrong hands, but so can a surgeon’s scalpel. They can also save lives. The power float used by veterinarians is not available to lay people and results in a better more consistent job every time. Operator fatigue and blunt hand floats are a thing of the past.
The final myth I want to run past you is that tall or dominant teeth can be safely reduced in a single dental session. This is simply not true. If too much tooth is removed in one sitting the pulp cavity and nerve can be exposed causing a painful death for the tooth that eventually means tooth extraction.
One thing that you always need to remember when dealing with equine dentistry and horses in general, is that not every horse has read the text book, and having access to the education and experience of a veterinarian is of primary importance.