A Horse’s Teeth: What Can We Learn, Age, Health, and More?

Last updated: March 1, 2023

By: Miles HenryFact Checked

While visiting a friend recently to see a new horse, the first thing he wanted me to show me was the horse’s teeth. I looked but wasn’t so sure what I was looking for. So, I decided to research to find out “what we can learn from horses’ teeth?”

From looking at a horse’s teeth, we can learn their age by the number and amount of wear of the teeth. They also disclose a lot about their overall health, expose bad habits, and reveal the horse’s gender. All the information is there; we just need to be able to know how to interpret it.

Many horse owners know you can tell a horse’s age by its teeth, but there is a lot more to be learned by looking at a horse’s teeth.

Horse teeth facts.

A horse’s teeth reveal a lot of information; we just need to learn how to interpret it. To begin with, adult horses have forty teeth. Just behind the horses, twelve incisors, are four small canines.

Then there is a gap– the space in which the horse’s bit sits when ridden–and beyond it are twenty-four molars or grinding cheek teeth. The front twelve of these cheek teeth (three on each side of each jaw) are represented as milk teeth and replaced simultaneously as the incisor milk teeth.

Still, the back twelve do not appear until later, their first arrival being as an adult, permanent teeth.

Horses’ teeth reveal their age.

So how do you know a horse’s age by looking at its teeth? As horses age, the appearance of their teeth changes, and it is easy to estimate their approximate age from the length, shape, and color of their incisors. The chart below provides a description of horse teeth in comparison to their age:

Below is a helpful chart you can use to determine the age of horses by looking at their teeth.

AGE	DESCRIPTION
At birth	The newborn foal has only two small incisors in the upper jaw and two in the lower jaw. These are the milk incisors and will be replaced later by the adult teeth.
At 4-6 weeks	Two more incisors are added in each jaw. The first, or central, incisors are now flanked by the second or middle incisors.
At 6 months	Two more incisors are added in each jaw, outside the others. These are the third, or corner, incisors. This now gives the young horse its total number of incisors: twelve (six uppers and six lower). These are still temporary or milk teeth. They all have “cups,” that is to say, small concavities at their tips. These little dips will disappear as the teeth are worn down, and this is one of the key factors in determining the age of a horse.
At 1 year	The first incisors have lost their cups–they have been worn down to the point where the tips are smooth. The second and third incisors still retain cups.
At 1.5 years	Now the first and second incisors have both lost their cups and been worn smooth, but the third incisors still show cups.
At 2 years	All cups have been worn down, and all incisor tips are smooth.
At 2.5 years	The first incisors of the milk tooth set have been replaced by the larger permanent teeth with cups.
At 3.5 years	The second incisors of the milk tooth set have now also been replaced and also display cups.
At 4.5 years	All milk teeth incisors have now been replaced with larger permanent teeth and all display cups. Technically the horse is now an adult.
At 7 years	The first permanent incisors are now smooth from wear, but the others still show cups.
At 8 years	The second permanent incisors are now smooth from wear as well, but the third still shows cups.
At 9 years	All incisors have now worn smoothly. All cups have gone. On the first and second incisors, there is a new feature: the dental star. This is a short dark line between where the cup used to be and the front edge of the tooth. It is the upper end of the pulp cavity, revealed externally by the wear on the tip of the tooth. Dental stars first started to show at six years of age but inconspicuously and only on the first incisors. They are now clearly visible on both the first and second.
At 10 years	The dental star is now visible on all incisors.
At 13 years	The ends of the teeth become rounder in section, and the dental star becomes a centralized dark spot.
At 15 years	The outer side of the third upper incisors shows a conspicuous longitudinal groove from the gum line down the tooth to about halfway from its tip. This dark groove began when the horse was only ten but was then barely visible.
At 20 years	The groove on the third upper incisor now extends for the whole length of the tooth.
At 25 years	The groove has disappeared from the upper part of the tooth and is visible only in the lower half.
At 30 years	The groove has disappeared completely.

Compiled from “Horsewatching” by Desmond Morris

Unless you are provided with valid papers, checking a horse’s teeth is the best way to determine its age. Be wary of “Bishoping,” a process named after an unscrupulous man notorious for excavating smooth-tipped teeth with a sharp instrument to recreate the missing “cup” or dip of a horse tooth to fool a prospective buyer.

Horse’s teeth reveal their gender.

You can tell the gender of a horse by looking at its teeth, but this expertise takes time and patience. To determine the gender of a horse from their teeth requires you to count their teeth.

A mature male horse will have 40-42 permanent teeth, and mares have 36-40. This is a general rule because some horses will not develop all teeth and may lose some over time.

I suggest an easier method to determine a horse’s sex, lift the tail, and take a quick look. It is much easier than staring into the mouth of a horse and counting its teeth. The only way I see this to have any practical purpose is to determine the sex of a skull found.

Horses’ teeth reveal their overall health.

A horse will indicate when he is having problems with his teeth; you just need to be aware of these signs; some are obvious, and others are not so much. Below are some obvious signs your horse is having problems with his teeth.

Quidding is a sign of mouth pain.

Quidding is the process of loosely chewing their hay or feed and balling it up instead of grinding it like normal. It will spit this ball out in the form of a wet wad; it often looks like a bird’s nest.

It’s a typical sign of mouth pain. It can be caused by overgrown or fractured teeth, infected gums, teeth with sharp edges, or missing teeth.

Dropping feed while chewing is an indication of a dental problem.

Dropping feed while chewing is a natural behavior for some horses; however, if it is not for your horse, it is likely caused by a dental problem. When a horse has problems with its teeth, it may not chew properly, causing the grain to spill from its mouth.

A dental-related sinus infection often causes nasal discharge.

Nasal discharge can occur for numerous reasons. However, if you notice a release of mucous as opposed to a slight amount of transparent substance, it is likely a sinus infection. The condition can be related to a dental disease caused by the tooth roots projecting into the maxillary sinus;

Stinky breath is a symptom of mouth infections.

Stinky breath can be the first indicator of a dental problem you will notice. It is a sign of infection in your horse’s mouth. The smell can be quite repugnant and is indicative of an abscessed tooth,

The smell is coming from bacterial overgrowth in the horse’s mouth. Dental problems are the most likely cause, but they can be a sign of other health conditions as well.

Horses with tooth pain often lose weight.

If your horse has bad teeth, it can not chew properly, making it difficult to eat and maintain a healthy weight. A horse crushes its food with his teeth; this allows his body to easily absorb the nutrients from his diet.

Without properly crushing the food, it may pass through him without proper nutrient absorption. Another worry is that if the horse does not adequately chew his food, he runs the risk of choking and colic. (click here to learn more about colic). 

Facial swelling can be related to dental infections.

Facial swelling is typically the result of an infected tooth. Numerous other issues can also cause swelling. It is best to have your horse examined by a veterinarian at the earliest onset of this condition.

Horses acting of character, thrashing their heads when riding, may have mouth pain.

A horse with a painful mouth will act fussy and perform poorly. If you have trouble controlling your horse, he is throwing up his head, resisting the bit, or generally not paying attention to your directions; he could have a dental issue.

Check his bit for proper placement and check his teeth and gums for any irregularities.

A reluctance to eat can be caused by sharp teeth.

Sore, infected, or sharp teeth can make it painful to eat. Sharp points on a horse’s molars may poke the roof of his mouth or his cheek when he chews his food, which will result in him becoming less likely to eat.

Horse’s teeth will show signs of bad habits?

A horse’s teeth reveal signs of cribbing.

The most apparent bad habit revealed by looking at the horse’s teeth is cribbing. Cribbing occurs when a horse grabs a fixed object with his incisors (usually a wood fence post) and inhales. To learn more about cribbing, click here.

A horse that cribs will repeat the wind-sucking process over and over. This habit causes the incisors to wear down and leads to problems chewing food properly.

Be aware of cribbing signs; this is a tough habit to break a horse from doing. If you are looking at buying a horse, I recommend you avoid a cribber. (Click here to check Amazon for prices on cribbing collars)

Horse teeth are subject to an array of dental problems.

Hook

A hook condition is similar to humans with an overbite or bucktooth-type syndrome. I hear it mostly referred to as “parrot mouth” in horses. It is when a horse’s upper jaw extends over the lower jaw.

The upper teeth will grow unusually long and sharp. This can lead to the teeth actually piercing the lower jaw of the horse.

Wave mouth

Wave Mouth creates a dominant tooth; it occurs when one tooth (dominant tooth) wears down the opposing tooth. It can lead to the opposing tooth grinding down to the gum.

This causes the horse’s teeth not to align properly when the mouth is closed and results in an abnormal chewing pattern. Food may fill the void left by the missing tooth and, eventually, result in an infected tooth socket and its sinus.

To remedy this problem, the dominant tooth must be cut to the level of the rest of the teeth. The opposite tooth is allowed to grow back to the level of the dominant tooth.

This problem will need to be monitored for the life of the horse. A severe wave mouth condition can take years of treatment to correct appropriately. It is prevalent in older horses.

Ramp

A ramp is a term used to describe a horse’s lower jaw in relation to a hook. Ramps lead to the same complications as hooks.

Step mouth

Step mouth occurs when a horse is missing a cheek tooth, and an opposing tooth grows into the space left by the missing tooth; it creates a condition that prevents the lower jaw from moving either forward or back.

Shear mouth

Shear mouth is a condition in which a horse does not chew evenly on both sides of the mouth resulting in severely sloped teeth. The outer edges will be higher than the inner corners.

This creates sharp points on a horse’s teeth, causing damage to the inside of their mouth. This condition impedes chewing and digestion, leading to weight loss and malnutrition.

Wolf teeth

Wolf Teeth are small cheek teeth, usually on the upper jaw, appearing in some horses. The horse’s teeth will interfere with the bit and cause pain. It is common to have these teeth removed without the horse suffering any negative effects.

Equine dental issues are treated with extraction and floating.

There are two common methods to treat most horse dental problems, tooth extraction and floating of the teeth. Tooth extraction can be done with extractors or repulsion extraction surgery.

A repulsion extraction requires the surgeon to enter the sinus cavity and knock the tooth out using a dental punch. An infected tooth or a tooth with no remaining crown are candidates for a tooth removal.

Floating horse’s teeth remove the sharp edges.

Floating teeth is grinding or rasping horses’ teeth to form them to function properly or prevent a painful condition in the horse’s mouth.

Generally, the horse’s teeth are floated to remove sharp enamel points from a horse’s teeth.   Until recently, floating was exclusively done manually with files and rasps.

There is also specially designed power equipment used to float horses’ teeth that is less disruptive. (Click here to check the price on Amazon horse 3 pc. teeth rasp for floating teeth)

Horses should have regular dental checkups.

Adult horses should have their teeth checked regularly and may need routine tooth floating to ensure a proper grinding surface and prevent any developing problems.

Floating is used to smooth out sharp edges and prevent overgrowth, helping to prevent quidding. It is also used to treat hooks from the cheek teeth and can be used to improve a bit’s comfort. Floating is a recommended treatment for wave, shear, and step-mouth conditions.

If your horse is under 5 years old, he should have his teeth examined every six months to see if they need to be floated. After 5 years old, your horse’s teeth should only need to be floated once a year unless he displays symptoms of an adverse dental issue.

Why Does a Horse Show his Teeth?

Often when I pass a particular horse, he grins at me and flashes his teeth. This smile prompted my grandson to ask me why the horse shows his teeth. So, I decided to look into this puzzle and find out.

Horses show their teeth for various reasons, and most are just gestures or because of aggravation. However, there is a critical time they show their teeth, and that is when they have colic. The other common reasons are when they smell, are in pain, feel threatened, or make a sound.

• Smell: A pungent odor in the air, he will likely curl a horse’s upper lip exposing his teeth; he will also raise his head and pull it back. This is called a Flehmen response.
• Pain: Some horses will expose their teeth when they are in pain.
• Threat: When a horse wants to signal he is mad and ready to attack, he may show his teeth as a sign of aggression.
• Colic: This is one sign that a horse has colic. He will oftentimes display a Flehmen response.
• Vocalizing: A horse often manipulates his upper lip, exposing his teeth when making sounds.

If you’re interested in learning more about horse teeth, check out my article: Horse Teeth – How Many, What Kinds, & Much More!

Below is a helpful YouTube video explaining how to age a horse by its teeth.

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