Q12) Can a horse's age be determined by
A horse's teeth can be used to determine a
horse's age up to about nine years. After that, age can only be
estimated. The phrase, "long in the tooth," probably emanated
from the horse traders of long ago.
Young horses have temporary milk teeth which are
smaller, whiter and smoother than permanent teeth.
By the time a horse is one year old, it has a
complete set of 24 milk teeth. At two, the teeth are more fully erupted and the
upper and lower sets of teeth are touching which causes wear. At about 2
1/2 years, the milk teeth are replaced by the permanent teeth. By age 3,
the central incisors have erupted, the two middle incisors erupt by about age 3
1/2. At age 4, the incisors are fully erupted and the canine teeth begin
to appear (usually in males only). At age 4 1/2, the corner incisors begin
to erupt and are fully erupted by age 5.
After age 5, the horse's age can be estimated by:
the amount of wear on the cups of the teeth
the shape and inclination of the incisors
the groove that appears in the upper corner
At age 10, a groove develops on the gum
line. This is called Galvayne's groove and as the horse ages, it extends
downward. By age 20, the groove is all the way down the surface of the
tooth. After this age, the groove gradually begins to disappear and by age
30, the groove is completely gone.
Environmental factors and habits the horse may
have acquired affect the teeth and can interfere with determining the horse's
age. Horses that crib or live in sandy areas are more likely to wear their
teeth down making it difficult to estimate the horse's age.