Mythbuster Monday: A Horse’s Teeth Tell Its Exact Age

On Mythbuster Monday, we tackle a variety of equestrian myths to either bust or confirm. Today’s discussion: Does a horse’s teeth tell its exact age?

It’s Mythbuster Monday, where Horse Nation dives into different equestrian myths and provides research-based evidence to either bust or confirm those myths. Today’s topic: Does a horse’s teeth tell its exact age? Until what age do we know the horse’s exact age? When does it get less accurate? Read further to find out!

Myth: A horse’s teeth tell its exact age

Myth or Fact: Both


A horse’s mouth is made up of incisors, molars, premolars, and canine teeth. The incisors are in the front of the horse’s mouth and are used for grasping and tearing food. The dental arcade, made up of the molars and premolars, are utilized for chewing and the canine teeth are found in the space between the incisors and the premolars. Each of these teeth has its own mechanism for aiding the horse in breaking down food, but do they also tell us the exact age of the horse?


An article by Utah State University gives great insight into whether or not we can tell a horse’s exact age by its teeth. They state that a horse’s age, nutrition, and health all have an impact on the teeth so an exact age can be unlikely to confirm. They write telling a horse’s age by his teeth is not an exact science but there are some indicators that happen at different periods in the horse’s life span. Attached is a table that shows normal wear on the teeth at approximate ages:

Deciduous 1st incisor (or centrals) birth or first week
2nd incisor (or intermediate) 4 to 6 weeks
3rd incisor (or corners) 6 to 9 months
1st premolar birth or first 2 weeks for all premolars
2nd premolar
3rd premolar
Permanent 1st incisor (or centrals) 2 ½ years
2nd incisor (or intermediate) 3 ½ years
3rd incisor (or corners) 4 ½ years
Canine (or bridle) 4-5 years
1st premolar (or wolf tooth) 5-6 months
2nd premolar 2 ½ years
3rd premolar 3 years
4th premolar 4 years
1st molar 9-12 months
2nd molar 2 years
3rd molar 3 ½-4 years

Table by J. Warren Evans

The University of Missouri published an article about the old fashioned way of telling a horse’s age. They state that while there are distinct changes that happen, probability of error rises once the horse hits 10 years of age. They state that research shows stabled animals are appearing younger in the mouth and horses that graze in sandy areas or are out grazing 24/7 are appearing older in the teeth than the guidelines suggest.


Extension Foundation also weighs in on the subject in an article they published. They state there are four major ways to tell a horse’s age: occurrence of permanent teeth, disappearance of cups, angle of incidence, and shape of the surface of the teeth. They write that being able to tell a horse’s exact age peaks at nine to 10 years old. After that the methods are less precise because the chance of mouth issues increases.


A research study performed by J. D. Richardson studied 80 horses of known age. The results showed accurate correlation between teeth and age for horses up to five years old. The older the horses got, the less accurate the teeth were. The disappearance of the “cup” proved to be one of the most accurate markers while the average age of the dental star usually appeared one to two years earlier than when current research states it should. Also, the caudal upper incisor hook appeared in almost every horse over the age of six so it did not aid in an approximate age.


After diving into the research, it’s important to note that using a horse’s teeth to tell his age is just a guideline. There are factors that can make the teeth age faster than the suggestions. However, earlier in life, the reading is more accurate and gets less accurate as the horse gets older.

Do you have an equine myth you’d like us to tackle? If so, send it our way! Email your suggestions to [email protected]. Put Mythbuster Monday in your subject line.