If given the choice, horses will spend on average 16 hours per day eating. This causes a huge amount of wear on their cheek teeth, which do all the grinding. Domesticated horses often have increased wear compared to their wild counterparts due to altered grazing patterns, with more grain and hay in their diets. Natural selection for good mouth conformation is also omitted from modern breeding programmes. As a prey animal, horses are very good at hiding any sort of dental pain, so you won’t necessarily know that anything is wrong in your horse’s mouth until the problem is very severe and painful.
So what can go wrong?
The most common problem that we find in horse’s mouths are sharp enamel points, and almost every horse will have them if dental care has not been given recently. These develop due to the grinding movement of the horse’s teeth across each other, and this happens faster when on more coarse diets such as grain, or if the silicate content of the feed is higher. These sharp edges can ulcerate and lacerate the soft tissues of the mouth, namely the cheeks and tongue. This can result in quidding (dropping food), slow eating, head shaking and resistance when being ridden.
Just as people can get problems with teeth growing in the wrong direction or not coming out when they should, so can horses. Retained or malpositioned teeth can interfere with subsequent tooth eruption, causing pain and malocclusions (where the teeth do not contact each other properly).
Minor abnormalities in occlusion (contact of the teeth) can develop into serious problems, such as overgrown teeth (hooks or tall teeth) which may protrude into the gums or block the movement of the jaw; and abnormal shapes of the arcades such as wave mouth, step mouth and excessive transverse ridges. These can interfere with normal grinding, and may also lead to periodontal disease.
Periodontal disease is a common, and extremely painful condition. Did you know that research has found that around 70% of adult horses have some degree of periodontal disease? This condition involves the tissues around teeth: the gums, periodontal ligament and bone sockets. The gums form pockets around the teeth leading to food entrapment and inflammation of the tissues. Eventual tooth abscessation or death can follow.
Some horses have a condition called odontoclastic resorptive disease. This is extremely painful and involves the body resorbing teeth with destruction of the tooth root.
Trauma to the mouth can lead to fractured teeth, exposing the pulp chambers which are the vital core of the tooth. This can cause tooth death if not treated within 48 hours.
About the Process
This lower jaw bone is from an aged horse that had significant dental disease. In this photo we can see a large overgrown hook on the first lower cheek tooth, and missing teeth due to periodontal disease and bone loss around the teeth. The opposing arcade had wave mouth formation, which predisposes to diastema formation and periodontal disease.
The external parts of the head and mouth are examined first as part of routine dental equilibration.
These are the incisors of a healthy 12 year old mare – her incisors are even with no periodontal disease. There was a small amount of calculus present which was removed.
A dental speculum is placed on the sedated horse, which allows a safe and thorough examination inside the mouth.
A strong light is used to illuminate the inside of the mouth for full examination.
A view inside the mouth of a 7 y/o welsh pony – this pony has a nice even set of teeth although sharp edges needed to be rasped down. Bit-seating to round off the front edges of the first cheek teeth was also done to prevent pain when the bit pulls the lips and cheeks back against the teeth.
A dental halter or a padded head stand can be used to support the head of a sedated horse during the dental work.
The use of a powerfloat can be well tolerated in a sedated horse.