What is the age of the horse in the described case?

• A. 8
• B. 12
• C. 18
• D. 20

Answer: (C)

Estimating a horse’s age primarily hinges on dental development and wear. As horses age, their teeth erupt in a known sequence and wear patterns change in predictable ways, giving clues to their approximate age.

A key sign is Galvayne’s groove on the upper incisor. It first appears around age 10, and then progresses downward along the tooth—roughly halfway by mid-teens, reaching the bottom around age 20, and eventually fading by older ages. The absence of visible cups in the permanent incisors is another cue, as the cups usually disappear by about 6–9 years. In an 18-year-old horse, you’d typically expect to see a Galvayne’s groove present and extending well down the tooth but not yet at the very bottom, with cups long gone.

So the described case matches this pattern: the groove is visible and extended, cups are no longer present on the incisors, which aligns with about 18 years. If the horse were younger, the groove would be less developed or absent; if older, the groove would be deeper toward or reaching the bottom of the tooth.