Ageing A Horse By Its Teeth

Jessica McDaniel
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Common Indicators of Aging a Horse by Teeth

Examine the horse’s teeth to estimate the age, because it is one of the most reliable methods of aging a horse. If the horse is older than 5 years, generally the ages of a horse determined by teeth can be assumed to be 7 years for teeth, 8 years for the eye teeth, and 9 years for the permanent molars and bicuspids, although there is a wide range on either side.

Dissections confirm the accuracy of the computation, but those rarely occur. Nineteen distinct teeth are found in the horse, but experts only refer to 14 of them, classes II to XVI. The ages of the horse are counted on the surface, or a lineal measurement of a permanent tooth. Class II consists of the pre-molars, forming the 6 in front of the incisors. Class III consists of the first two molars, the incisors. Class IV consists of the premolars and the canines, the teeth with cusps, or fangs, the type which is standardized by dental terms, and all are arranged in rows. Class III teeth are the premolars, dividing the difference between the incisors and the molars. Class IV are the canines, or four-cusped teeth, which appear after the molars. None of these is counted as a tooth, but belongs in the general age computation.

Aging a Horse by Teeth: Shape of the Teeth

Horses can be aged by tooth shape – the lower top jaw looks like the “cheek teeth” while the upper top jaw looks like the “eye teeth”. From the age of six to about twenty, the upper four front teeth are the cheek and gradually move forward into the eye area as horses age. Should you need to know your horse’s age to the very day, a tooth chart is invaluable. There are a number of different methods of age identification. However, for accuracy, it is best to have an experienced equine veterinarian do the examination.

For fun, however, you can look at the horse’s teeth for a good clue to its age. A geriatric horse has a bit of yellow on the outside edges of the eye teeth, or second cheek teeth, which are called premolars. As the horse gets into its twenties, the teeth are usually totally yellow or slightly browned.

If you’re a dentist, you can actually look at the horse’s teeth to determine its age. I’ll leave that discussion to the professionals!

Permanent Teeth

Horses are born with all forty-eight teeth. So regardless of their age, your horse should have incisors (8 teeth), canine (4 teeth), premolars (4 teeth), molars (12 teeth) and the third premolar. These teeth are considered their permanent teeth. There should be twelve fluid-filled teeth replacement teeth that are more commonly known as the fourth premolar or the wolf teeth.

As horses grow, the wolf teeth start to wiggle out one by one. Since the main role of the wolf teeth is to help horses grind their food and because horses are herbivorous, the wolf teeth are often inefficient and often worn out quickly. This is why they often fall out early.

You may be able to see the wolf teeth in your horse's mouth in its early days. But as the wolf teeth fall out, a horse will turn into the age of three to four. Three to four-year-old horses will start to have their first four permanent incisors that are deemed temporary teeth.

This allows the horse to grind a broader surface area. The temporary teeth are used for as long as the horse is growing and not longer than two years. As soon as the horse is full grown, the temporary teeth start to fall out and make ways for the permanent teeth to take their place.

Aging a Horse by Teeth: Cups in Teeth

Like human teeth, a horse’s teeth are divided into sets, known as a dental formula. Horse teeth are easier to see from the outside for the experienced eye but the dental formula for an adult horse, has 28 total teeth. There are only three sets of teeth in a horse.


The only set of teeth that are visible on the outside of the horse’s mouth are the cups, which are the cheek teeth. Teeth are also referred to as cups to differentiate them from canines. Canines, like a horse’s incisors, are used for biting and tearing, unlike cups. Cheek teeth are chin teeth, which are looser in the horse’s mouth to allow for easier chewing.

Angles of Teeth

The front or cheek teeth of a horse, called incisors, are split into the top and bottom sets. Each incisor is identified by the letter at the front, middle and back of each set.

The lower set is called P – Premolars, while the upper set is called M – Molars.

The premolars and molars are taller than they are wide, and they only have one root that goes to the jaw bone.

Lithium degeneration of teeth is a very gradual process and is well understood by equine veterinarians. It follows a characteristic pattern in the heights of the teeth. Vets, therefore, look at the heights of the various teeth in the mouth to get a good idea of the horse's age.

When they are comparing heights of the teeth they use the heights of the deepest tooth in each group, P 1, M 1 and M 2.

The lengths of the teeth do not normally change but the heights do vary. In the case of the incisors, pairs of incisors move in and out of wear as they continue to be used for grazing.

Aging a Horse by Teeth: Age Accuracy

An equine dental examination is meant to compare and determine the age of a horse by its tooth as it ages. Knowing the age of the horse can be helpful in determining how old your horse actually is, when he was born, how long he may live, and when he may start to experience health issues or show signs of aging.

Generally, the best dental examinations are done by a veterinarian, but you can get a rough age estimate by looking at your horse’s teeth. It’s rather easy to do. Of course, the older the horse you are inspecting is, the more accurate the result can be.

The best part is you don’t need to put your hands into the mouth of the horse for this to be done. You just need to know what you are looking for and where.

The stage of the tooth that arrived is referred to as the D3, also known as the “ghost tooth.” This means the tooth is no longer growing and is simply there.

The first teeth to start developing are the incisors, cutting teeth, and the premolars. These are referred to as the “baby teeth.”

Four Groups Method

The best way to find out how old a horse is, is not by counting the rings on the tree or through genetic tests. If you want to get the most accurate reading, you will need to perform a little dissection.

The first step in this process is to find the jaw or the roof of the mouth. You will see the teeth are aligned in a manner which takes the shape of a horseshoe, and separates the teeth into two groups which are on the outside of the horseshoe and the two groups which are inside.

The inner four teeth, which are the smaller ones near the back, are considered permanent teeth, and are what we will be using to figure out the horse’s age.

On the outside, there are the larger teeth, and they are often referred to as the cheek teeth or the false teeth. These teeth wear out every six months or so, and fall out. This is why they are considered false teeth.

The permanent teeth on the inside, grow continuously and don’t wear out.

On the outside of the horseshoe, we are going to take into account two of the cheek teeth and their original age. After this, we will take into account the growth ring, which is a discolored portion of the tooth, that forms after the horse is six months old.


It is possible to tell a range of ages of the horse, just by looking at its front teeth or age marks. Horse teeth are quite large and are used for grinding, therefore they have specific terms for the different types of marks and scratches.

— Pony: usually a horse will have 8 pairs. Each pair is called premolars. You would normally start seeing signs of wear in a pony at the age of 3 ‖ 4 years.

— Adult horse: for an adult horse, the first signs of wear will usually appear at the age of 5 years old.

— Adult: wear on the teeth will start to show at around 15 years of age.

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