Horse teeth are more than just a tool to chew food; they offer a glimpse into a horse’s health. A study of a horse’s teeth can reveal a great deal about its diet, health and even age. Dr Bruce Whittle, a practitioner at Honey Creek Veterinary Hospital in Trenton, Missouri, shared this important information with attendees at the 2016 American Association of Equine Practitioners convention in Orlando, Florida.
In a horse, the front teeth, called incisors and the back teeth, premolars and molars, work together to crush food, allowing digestive juices to penetrate the crushed material and extract nutrients. The equine mouth is adapted to eat tough fibrous grass with powerful mastication muscles that allow circular movement of the lower mobile jaw against the fixed upper jaw, much like the motion of a grindstone.
Equine teeth are unique because they have multiple shapes, and two sets; deciduous (“baby”) and permanent. They also have a pair of vestigial wolf teeth (also called premolars) that serve no functional purpose.
Like other animal and human teeth, equine teeth are constructed of hard materials, including enamel, dentin and cementum. The enamel is the hard outer surface, the dentin is the yellowish or pinkish inside material and the cementum is a sticky substance that holds the tooth in place. Inside the abrasive exterior of the tooth is a complex network of blood vessels and nerves that maintains a healthy tooth from within.
Horse molars have a distinctive feature, the galvayne’s groove, that is one way to estimate a horse’s age. The groove is an area of extra enamel that forms on the front and top of a molar. As a horse ages the groove widens, revealing more of the molar surface and providing more abrasive grinding surfaces to break down foodstuffs. As a result, the molars become worn down and dull over time.
Lastly, the molars have a flat side or surface that is sometimes referred to as the dental star; it can be used to estimate a horses age by observing how much of the dental crown is exposed. The more the star reveals, the older the horse.
As the molars wear down the inner part of the tooth becomes hollow, and the reserve crown is progressively depleted, leading to a loss in chewing efficiency. This is why the molars often appear shorter and more blunt with age. As the teeth deteriorate and lose their abrasiveness they can cause discomfort in the mouth, which can lead to refusal of food or difficulty eating. This can lead to nutritional problems and poor overall health in the animal. Regular oral examination by a veterinarian is the best approach to ensure the teeth are healthy and in good working condition.