Finding the Groove

Professor Sydney Galvayne, (1846 – 1913) achieved a measure of immortality with his 1885 book, Horse Dentition: Showing How to Tell Exactly the Age of a Horse up to Thirty Years. This small book linked stages in a horse’s life with changes in his teeth. One of those changes became known as Galvayne’s Groove.

In the illustration, the third tooth from the left is an upper corner incisor. The dark line starting at the gumline and extending halfway down the tooth is Galvayne’s Groove. It emerges at nine to ten years of age. As the teeth continue erupting, the groove is exposed at a measured and predictable pace, extending the full length of the tooth by age 20, and disappearing entirely at about 30. This horse would be about 13 years of age.
Although it is not infallible, Galvayne’s Groove is still useful in combination with other indications of tooth wear to estimate a horse’s age.
To learn more about Professor Galvayne and other horsemen of the past and present, see The Revolution in Horsemanship.