Your horse’s frontmost teeth are called incisors, and the upper and lower jaws each have six of these teeth. Horses use their incisors for grasping and cutting grasses. Because incisors typically grow and wear predictably in healthy horses, they can be used to estimate a horse’s age. However, if a horse has been malnourished or has improper tooth alignment (e.g., parrot mouth), this method is not accurate for determining age.

Use care when checking your horse’s teeth. Gently pull your horse’s lip up to look at the front teeth, ensuring that your fingers are clear of your horse’s teeth. The following description of how your horse’s incisors wear over time is a general guideline for estimating your horse’s age:

• At 5 years of age, the cups of the middle incisors are worn flat, and the outer incisors begin to show wear.
• At 10 years of age, the central enamel ring is oval, the next-to-last incisor on each side is rounded, and Galvayne’s groove (vertical groove in the outer surface of the tooth) appears on the outermost upper incisors.
• At 15 years of age, the dental stars are round, dark, and distinct; Galvayne’s groove is halfway down the outermost upper incisors.
• At 20 years of age, the next-to-last incisor on each side is triangular when viewed from the top of the teeth. Galvayne’s groove extends the entire length of the lip side of the incisors.
• At 25 years of age, Galvayne’s groove disappears from the upper half of the tooth.