Why Do Horses Show Their Teeth? 15 Main Reasons

Horses can be pretty big and intimidating, so when they show their teeth, a lot of people instinctively believe that it means that the horse is going to bite them.

After all, why else would they be showing their teeth? But the truth is, horses don’t bite all that often, yet they can show their teeth many times a day. So what does it mean when they show their teeth? 

Well, as horses can’t just talk to you, they find other ways in which to communicate, combining body language with actions. Showing their teeth is a very strong form of communication, and it might mean that your horse is trying to tell you something or make you aware of something. 

However, sometimes horses show their teeth without even being aware of it because it is also part of their natural behavior!

So although sometimes a horse showing its teeth can be a sign of them threatening you or becoming aggressive, it could also mean that they’re having fun or are relaxed, or maybe they simply have some food stuck there!

With that in mind, we have divided all of the most common reasons for which a horse shows its teeth into four main groups: showing their teeth on purpose, showing their teeth while eating, showing their teeth naturally, and other reasons.

Within each group there are a number of different common reasons why your horse might be showing its teeth, so you can browse through them and figure out which one it is! 

Just remember that in order to figure out why your horse is showing its teeth, you need to take into account the context and situation, as well as other body language and forms of horse communication. Plus, you should observe your horse’s behavior carefully so that you can learn to better pick up on what things mean!

Now that all of that is clear, let’s get into all of the different reasons why horses sometimes show their teeth. 

Reasons For Horses Showing Their Teeth On Purpose

If your horse is showing their teeth intentionally and on purpose, then it is a form of communication. It can mean many different things, which is why you also have to look at the rest of the body language, within the context you are in, to determine what exactly your horse is saying. 

Here are four common meanings for when horses show their teeth on purpose:

1. The Flehmen Response

The Flehmen response is a behavior in which horses curl their top lip up (all while stretching out their neck and raising their head), so that they can pick up the different scents of chemicals in the air, such as pheromones.

When a horse does this, it’s usually because there is an unknown or interesting smell. Usually, it is common behavior amongst stallions, when there is a nearby mare in heat. 

Because the Flehmen response can sometimes make it look as though the horse is smiling, some people train their horse to do it, by training them with strong smells and rewards. However, if you do this you will no longer know when your horse is doing it because of a smell, or simply out of training!

2. Out Of Aggression

If your horse is intentionally showing their teeth, then it could be a sign of aggression, which needs to be taken as a warning. There are many different reasons why your horse might be showcasing aggression, and not all of them are bad. 

When horses are startled or being harassed, they can show their teeth as a way of saying they are unhappy, and that the situation needs to stop. It can also be in order to establish authority. 

A more common reason is when horses feel threatened, as it is a sign that they are uncomfortable, and that they will react if needed. 

3. As A Threat

Showing their teeth as a threat can be very easily confused with horses showing their teeth as a sign of aggression, as the contexts and situations often overlap. However, the actual reason behind showing their teeth in both situations is different.

In aggression, the horse is reacting. However, if they show their teeth as a threat, they are anticipating a situation before it takes place. 

So, for example, if your horse thinks that another horse is going to steal their food, they might show their teeth as a threat in order to say “back off”. It’s basically showing teeth as a warning. 

4. Clacking Their Teeth

Usually, a behavior seen in horses under the age of three, clacking their teeth is when horses open and semi-close their mouth as if chewing, making a clacking sound, and showing the teeth. 

This is most often behavior that takes place when the horse is in an unfamiliar setting, as a way to self-calm and seeks comfort.

It is also common for horses to do this in order to show other horses that they aren’t a threat. So it’s a bit like when a young dog shows their belly to a bigger, more intimidating dog, to show that they are not a threat and submit. 

Reasons For Horses Showing Their Teeth While Eating

When it comes to eating, horses all have their own different habits and behaviors, unique to their personality. Some horses are super neat when they eat, others are messy, some take their time to taste the food properly, others swallow it up in seconds. And the same goes for showing their teeth or not!

Some horses will show their teeth while eating, for no other reason than it being a habit they have developed. It doesn’t mean anything and is completely harmless. If anything, it’s kind of goofy! 

However, there are times in which showing their teeth while eating can actually be a sign of something specific. Usually, you will be able to check it out in order to figure that reason out. 

Here are the three most common: 

5. They Have Food Stuck

Just like us, horses can sometimes get food stuck in their teeth, which can be pretty uncomfortable so they will immediately try to get rid of it. In order to do this, they will usually flex their lips up and down, trying to dislodge the food from where it’s stuck. After all, they can’t just use a toothpick! 

If this happens, you can help your horse out by removing the stuck food, that way they can go back to enjoying the meal. 

6. The Food Tastes Bad

Do you know when you eat something that tastes really bad, and you instinctively open your mouth and stick out your tongue, showing your teeth, as a way to cope with the aftertaste and to try and get rid of it?

Well, horses do the same! If they eat something that tastes bad, they will separate their lips, stick out their tongue repeatedly, and show their teeth. 

This is very common when a horse is being dewormed, as the paste used doesn’t exactly taste good. If you want to avoid this from happening, you can fill a syringe with mashed-up apple or similar, so that your horse begins to associate it with something that tastes good.

When you use it for the deworming paste, it will happen so quickly that your horse won’t have time to realize that it isn’t one of the good-tasting ones!

7. Because Of Dental Problems

If your horse is chewing their tongue while they eat, showing their teeth as they do so, then this could be a sign of pain or discomfort, commonly due to a dental issue.

There might be other accompanying signs to this, such as the swishing of the tail, or the ears being all the way back. This definitely means that something is hurting your horse while they eat, so you will have to have the teeth checked over by the vet. 

Reasons For Horses Showing Their Teeth Naturally

Sometimes, horses showing their teeth is an explicit form of communication that they are doing on purpose, and given the context, you have to figure out what they’re trying to tell you.

However, sometimes horses show their teeth as natural behavior, which means it is simply as part of their unconscious body language when they are feeling certain things or are in specific situations.

They do it without thinking about it, so it’s not them trying to tell you anything. However, figuring out what it means can help you better understand your horse, as it can give you information on feelings, mood, and overall state. 

Here are some of the main natural reasons for which horses show their teeth:

8. They Are Happy

If horses are having a lot of fun and feeling especially happy, they might sometimes curl the corners of their mouth upward and show their teeth. This gives the impression that they are full-on smiling, and in a way, they are! 

9. They Are Relaxed

Horses can also sometimes show their teeth when they are relaxed and at ease, as a result of relaxing their faces and letting their bottom lip droop down. This can sometimes also depend on the shape of the horse’s lip, and whether it droops enough to show off the teeth in a natural way or not. 

10. When They Are Yawning

If a horse shows its teeth due to a yawn, you will most definitely know, because when horses yawn they yawn big!

They open their mouths up wide, pull their lips all the way back, sometimes stick their tongues out, and their teeth are completely visible. And yawning, just like in humans, is completely normal! It can happen for many different reasons and is nothing to worry about. 

11. They Are In Pain

When horses are in pain, they, unfortunately, can’t just come up and tell us. However, they show it through body language and different signs, that you need to keep an eye out for.

One of these signs is horses showing their teeth. Specifically, if they are showing their teeth as if wincing, curling their top lip up, and as a reaction to the pain being stimulated. So, for example, if they have a painful area, you touch it, and they show their teeth, that is a sign of pain. 

It is important to note that horses showing their teeth as a sign of pain is very similar to when they have the Flehmen response, with the only clear difference being that they might not be stretching out their neck. This is why it is so important to be observant, and to look out for other signs and body language to confirm your suspicions. 

And if you’re in doubt, whether because you’re unsure if it’s because of pain or not, or because you’re not sure what is causing the pain, call the vet and get your horse checked out. It’s better to be safe than sorry!

Other Reasons Why Horses Show Their Teeth

Learning to understand and communicate with your horse is never as easy as “this sign means this, and this body language means this”.

Horses are complicated, and they all have unique personalities, habits, body language, and reactions to certain situations and contexts. This means that although you need to know the basics, you also have to do some detective work specific to your horse, and be observant so that you notice when there is a change in behavior or body language. 

So, in regards to horses showing their teeth, although we have covered the basics of purposeful behavior, natural behavior, and showing their teeth while eating, there are plenty of other reasons why they could be showing their teeth. Of course, we can’t cover all of the possible explanations, because there are practically infinite ones! 

But here are some other common reasons why horses show their teeth, and what they mean:

12. It Happens While They Shake

Do you know how other animals such as dogs sometimes shake their entire bodies? Well, horses also do that, only some horses will also show their teeth while doing so! They can shake for a vast number of different reasons, whether it’s because they’re wet, covered in dust, itchy, or simply having a chill down their spine.

Most often, when they shake, they relax their whole body before shaking violently, and this means that their lips will have relaxed and parted, so when they shake the lips will flap and the teeth will show!

13. They Are Vocalizing

It might sound funny, but horses will sometimes show their teeth when they are talking to one another, moving their lips around along with the rest of their facial muscles, in order to be more expressive and vocalize exactly what they mean.

So…kind of like pulling funny faces at each other, but as a means of communication! And yes, this can 100% include showing off their teeth in many different ways. 

It’s actually super common. For example, when horses neigh, they first need to open their mouths up wide so that the sounds will reverberate, and their teeth tend to show as a result.

The same goes for when horses snort or blow out of their nostrils. Sometimes the teeth show is an unintentional part of the communication, but it is part of them vocalizing nevertheless!

14. They’ve Got Sunburn Around Their Lips

Horses, believe it or not, can also get a sunburn, especially around the lips! This most commonly happens in Paint Horses, as they have a large amount of white around the muzzle.

Essentially, their lips become dry in the sun and heat and then become chapped and sunburned. This makes it difficult for the horses to close their mouths, as they will be feeling a lot of discomfort and pain. So instead, their mouths will be half-open, and they will be exposing their teeth!

If this happens to your horse, apply some cream to the affected area. This will help moisturize the lips so that they no longer cause pain and discomfort. (Make sure it’s the right type of cream, specifically for horses!) 

15. They Are Carrying The Bit In Their Mouth

If your horse is young, or not used to the bit that goes into a horse’s mouth, then it is pretty common for them to curl their lips up and show their teeth. This is just a natural reaction to the newness of the bit, as they still need to get used to it. After all, it’s a strange object that has been placed into their mouth!

This reaction should lessen with time, as your horse becomes accustomed to the bit and learns to accept it, so it should be nothing to worry about! However, if the reaction persists, it could be that your horse needs a different type or size of bit, in order to be more comfortable. 


So…why do horses show their teeth? They can show their teeth for a number of different reasons, so many that it is impossible to cover them all, especially as horses all have unique reactions and expressions when communicating. 

Nevertheless, it is important to know the main and most common causes, so that you can learn to identify important signs in your horse’s body language and communication. 

When horses show their teeth, it is usually either due to a purposeful behavior (of them trying to tell you something), out of natural behavior (they aren’t aware of doing it), a natural reaction while they are eating, or something completely different.

It is important to observe the rest of your horse’s body language, within the specific context, and to learn to pick up on whether it might mean something important, or if it is nothing to worry about. 

If you really struggle to figure out why exactly your horse is showing its teeth, and you’re worried it might be because of pain or discomfort, then it is very important you contact the vet and have your horse checked over. It might be nothing, but it is better to be safe than sorry!

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