How to Stop Your Horse From Opening His Mouth (Without Using a Flash)

“Contact” is the third element of the dressage Scales of Training. In an ideal scenario, the dressage judge wants to see that your horse is working confidently forward through his back to seek an elastic, consistent contact without showing any signs of resistance.
Unfortunately, many dressage horses tend to work with their mouths open.
So, in this article, we take a look at why a horse opens his mouth, and we discuss how to stop your horse from opening his mouth without using a flash.
What causes contact issues?
A horse that habitually works with his mouth open generally does so in an attempt to escape from pain or discomfort in his mouth.
Such discomfort can be caused by:
- Dental problems
- The rider’s unsteady hands (constantly pulling or seesawing at the horse’s mouth)
- A poorly fitting bit
- Tension
- A combination of the above
Tack can also cause a horse to open his mouth when ridden.
For example, sometimes, if a horse is ridden in draw reins, he will come behind the bit when the draw reins come off, opening his mouth against the expected effect of the gadget on the bit.
The effects of contact issues
Often, the horse that works with his mouth open displays other evasions and problems in his way of going.
Some horses tend to work above the bit, raising their heads high away from the contact. That causes the horse’s back to become hollow and tight and their hindquarters to tense up. Consequently, the horse is unable to use his hind legs correctly, and his hocks will trail out behind him, rather than stepping underneath his body.
Other horses avoid taking the contact forward by curling up behind the bit, pulling their noses into their chests in an attempt to evade the bit and the rider’s hands or both.
In both these scenarios, the horse is not supple through his neck and back, is therefore unable to work with true impulsion. He will also most likely be unbalanced, as he cannot bring his hocks underneath his body, and the rider will be unable to use an effective half-halt.
Related Reads:
- How to Ride Your Horse on the Bit
- What is “The Correct Way of Going” in Dressage?
- How Your Horse Should Use His Hindquarters
Correcting the open mouth problem
Unfortunately, working with the mouth open can quickly become a habit for some horses. Once that habit becomes ingrained, it can be difficult to cure.
However, whatever the reason for your horse working with his mouth open, DO NOT resort to forcing the horse’s mouth shut by using a tight flash or crank noseband, as that will only lead to more misery for the horse and create even greater resistance and evasion.
Before you can work on solving the problem, you need to understand why your horse opens his mouth.
The headcollar test
Start by lunging your horse in just a headcollar or cavesson. Don’t use a bit or side reins. The idea of the exercise is to observe how the horse works without the influence of any form of tack.
If the horse happily trots around on the lunge on both reins with his mouth closed and stretching forward and round over his back, you can see straight away that the open mouth problem is caused in some way by the presence of a bit and bridle.
Now, repeat the exercise, but this time, lunge the horse in a plain cavesson bridle and his usual bit. Watch the horse closely to see how he reacts to having the bit in his mouth.
If the horse’s mouth remains closed and he’s happy to trot forward, fit a pair of loose side reins, and lunge the horse, encouraging him to work forward through his back toward the bit. Is the horse’s mouth closed, or does he immediately open it and raise his head away from the loose contact?
This exercise will give you a good indication of where the problem lies. Generally, a horse that is quiet in his mouth in all these scenarios has a problem with the rider’s contact and how it affects the action of the bit in his mouth.
Dental check
First of all, you should ask a qualified equine dentist to check your horse’s teeth to make sure that there are no sharp edges or hooks that could be causing the horse discomfort when you pick up the contact with the bit.
Once any issues have been treated, regular dental examinations should help to highlight potential problems, enabling you to take preventative action in the future.
Poorly fitting bit
If the horse’s bit doesn’t fit him properly, he may open his mouth to escape the discomfort it is causing.
For the horse to be comfortable in his mouth, he must be able to move his jaw freely, from side-to-side. When the horse has a bit in his mouth, he salivates, and so he needs to be able to swallow. When the horse swallows, his tongue is lifted toward his palate.
If the bit is painful, too thick, is held too strongly by the rider’s hand, or if the horse has his jaw clamped shut by a noseband, he will be unable to lift his tongue and swallow, and his jaw will remain tense. The horse will then push back against the bit with his tongue in an attempt to lift it so that he can swallow. That leads to tension not only in the horse’s tongue but in his neck and jaw too.
The bit should not protrude from either side of the horse’s mouth, and it should not be too thick or thin. If the bit is too small, it will pinch the horse’s lips. If the bit sits too high or too low in the horse’s mouth, it can crash against his teeth, causing him discomfort.
As well as fitting the bit correctly, you must choose one that suits your horse as every horse’s mouth is unique in size and shape.
To find the best bit for your horse, ask an experienced bit-fitting service for advice, and be prepared to experiment. Your horse will soon tell you what bit he prefers and how it should be fitted for his comfort.
Rather than buying umpteen bits until you find the right one for your horse, use one of the many “bit bank” services that you’ll find online and borrow a few different bits.
Related Reads:
- How to Choose and Correctly Fit a Bit for Dressage (Single Bit/Bridle)
- How to Introduce Your Horse to a Double Bridle
- How to Fit Your Horse’s Noseband
Unsteady hands
If your unsteady hands are causing the problem, you’ll need to work on developing a more independent seat. That will enable you to ride in a secure balance and with quiet hands.
Never use the reins for balance; your hands should always work independently of your seat.
To give you a clear understanding of just what your horse feels when you take up the contact, play the “bit game.”
Take the bit and reins off the bridle. Hold the bit in your hands and ask a friend to hold the reins. Your friend then applies pulls, seesawing, and bumps to the bit, simulating the motions that you typically use, then you’re asking your horse to turn and halt. That will give you a clearer appreciation of exactly why your horse has a problem with your hands!
So, how do you know if your hands are unsteady? Try dropping your little finger onto your horse’s neck and see if you can keep it there while the horse is trotting and cantering. If you can’t keep your pinkie in touch with the horse’s neck, your hands are bouncing.
Once you’ve improved your seat and your unsteady hands are no longer the issue, you can start to work on undoing your horse’s evasive habit.
Try lunging your horse in side reins with elasticated inserts or “donut” rings. The consistent, elastic contact provided by the side reins helps to teach your horse that reaching for the bit isn’t uncomfortable anymore. Working on a circle also encourages relaxation and helps to create a good rhythm.
Another helpful exercise that you can try is to work your horse over low cavaletti or poles on the ground. That encourages the horse to stretch forward and down. Once the horse understands that he can trust your hands to be quiet and soft, he will begin to reach for the bit.
Related Reads:
- How to Improve Rider Balance
- How Much Contact Should You Have?
- How to Keep a Consistent Rein Contact
Tension
Also, tension can cause a horse to develop the habit of working with his mouth open, even though there is no physical discomfort involved.
A horse that is tense may sometimes express his anxiety by showing resistance to the contact and opening his mouth.
In this scenario, your goal is to encourage relaxation.
How you can solve the problem of tension depends on what the root cause is. It may be that desensitization will help to solve the problem, or perhaps working the horse in the company of an experienced older animal may be effective.
In conclusion
The way to stop a horse from opening his mouth is not by clamping it shut with a flash, drop, or crank noseband!
Opening the mouth when ridden is generally a symptom of an underlying problem, such as dental issues, poor riding, or a badly fitting or unsuitable bit that is causing the horse pain or discomfort.
Once you’ve diagnosed the problem, you can set about solving it, which will ultimately result in a happier horse and a softer, more elastic contact.
If your horse tends to work with his mouth wide open, tell us your story in the comment box below.
Related Reads:
- How to Build a Good Dressage Foundation
- How to Ride Your Horse on the Bit
- How to Teach Your Horse to Accept The Bit & Bridle
- How to Stop Your Horse Coming Against the Bit
Hi my friends horse has a large tongue and constantly plays with it when being worked even when there is no contact . Im sure he pushes the bit out to avoid the join and so he can avaid work
Tried many bits and he had his teeth done ! My friend is a novice and can be bit heavy handed and heavy in the seat !
Any advice you can suggest?
Hi Claire,
Thanks for reading our post and commenting.
Unfortunately, this is almost a near-impossible problem for us to help with over the internet since there are many different reasons why this could be happening. Anxiety, tension, incorrect training, saddle fitting/back issues, etc are just some of the other reasons why this behaviour could be occurring.
Our advice would be to look for a very experienced dressage trainer who could help work through solving the problem with you.
I am sorry that we couldn’t help you out more, but there are simply too many possibilities for why he may do this.
HTD x
Hi, my horse opens his mouth often when i’m riding, i used the technique that was suggested in the artical with my pinky fingers and they stayed still. I am constantly adviced to get a grackle bridal for him. He had his teeth and back checked 4 months ago and was all okay. Any advice on the next steps?
Hello Sophie,
Assuming that there are no physical problems and that you have nice still hands providing the horse with an elastic contact to work into, then the next steps that we would advise is teaching the horse HOW to connect to the bit correctly. This comes from teaching the horse how to use his whole body correctly. If you search our website for articles about ‘contact’ (also try searching for the keyword ‘bit’) we have lots of information to help you do this, but here are three articles to help get you going.
– How to ride your horse on the bit – https://howtodressage.com/dressage-theory/ride-horse-on-the-bit/
– How to teach your horse to accept the bit – https://howtodressage.com/dressage-theory/accept-the-bit-bridle/
– How much contact should you have? – https://howtodressage.com/for-the-rider/how-much-contact-should-you-have/
I hope that helps
HTD x