You can estimate a horse age by examining its teeth — a skill horsemen have relied on for centuries, and the origin of the saying “never look a gift horse in the mouth.” As a horse ages, its teeth erupt, wear and change shape and angle in fairly predictable ways. It is an estimate, not an exact birthday, but a knowledgeable eye can often get within a few years.
Aging by teeth relies on several changes: when the baby (deciduous) teeth erupt and are replaced by permanent teeth, the wear patterns on the chewing surfaces, the appearance and disappearance of marks called cups, the presence of Galvayne’s groove, and the changing angle of the incisors. Accuracy is best in young horses and becomes rougher as a horse ages.
Diet, chewing habits, cribbing, and individual variation all affect wear, so two horses of the same age can look different in the mouth. Aging is most reliable up to about age 5, when tooth eruption is the guide, and becomes a broader estimate after that. For an accurate assessment, nothing beats an experienced equine dentist or vet.
Aging is only one reason to look in the mouth. Regular dental care keeps a horse eating and holding condition throughout life — see why floating matters. Dental problems are also a common hidden cause of weight loss, which is one more reason to learn to body condition score and schedule routine checks with an equine dentist.
Find an Equine Dentist
Find an Equine DentistBy examining tooth eruption in young horses, wear patterns and cups, the appearance of Galvaynes groove around age 10, and the changing angle of the incisors as the horse ages.
It is most accurate up to about age 5, when tooth eruption is the guide. After that it becomes a broader estimate, and an experienced dentist or vet gives the best assessment.
It is a groove that appears at the gumline of the upper corner incisor around age 10 and gradually extends down the tooth as the horse ages, then grows out again, helping estimate age.
A horse typically has a full set of permanent teeth by about age 5, after the baby teeth have been replaced.
Because checking a horse teeth reveals its age and condition. Inspecting the mouth of a gift was considered impolite, hence do not look a gift horse in the mouth.
