Ask A Teamster The Bit

Ask A Teamster: The Bit

by Dr. Doug Hammill D.V.M. of Montana

Hello –

I work at a farm that uses their team of Percherons to farm, give hayrides, spread manure, etc. One of the horses gets his tongue over the bit. I’ve been told he’s always done this since they had him. I have always thought: #1. You have very little control, and #2. It would hurt! The horse is very well behaved, does his work with his tongue waving in the air, and sometimes gets his tongue back in place, but at that point it’s too late. They use a snaffle bit. Any suggestions? Maybe a nose band? Different bit? Is there anything to be concerned over? Should they continue to let him do this since it’s been going on for a few years. Let me know your thoughts!

Thanks, Jeanine Dziak

Thank you for being caring and concerned enough to seek information and perhaps a solution to this horse’s dilemma. Since he is apparently working safely and performing his job well, my primary concern is his comfort and well being. Once the tongue is over the bit, the inability to return it to it’s normal, and comfortable, position is at the very least distracting and annoying. With a bit under the tongue, horses are susceptible to the malpositioned bit causing traumatic injury to tender tissues beneath the tongue, and on the underside of the tongue itself. A less tolerant animal, or perhaps even this loyal worker, could, at some point, exceed their willingness or ability to withstand the frustration, discomfort, and perhaps at times pain, and a wreck could result. I feel horses deserve the time and effort necessary on our part to discover and eliminate the potential causes of this behavior, and to devise a way to prevent it.

Ask A Teamster The Bit
figure 1

When a horse initially begins to pull it’s tongue back, and out from under the bit, it is typically an effort to avoid some form of pressure or discomfort associated with the bit. In an attempt to get relief from, or escape, uncomfortable or painful bit pressure, pinching, or whatever, horses often go through contortions with the only movable structures in the area – tongue, lower jaw, lips, and sometimes muzzle. Unfortunately, horses that open their mouths and manipulate their lower jaws often find their jaws clamped shut with a tight nose band, without a thorough attempt to discover the reason for the behavior. Similarly, a horse that gets it’s tongue over the bit may have the tongue tied down, or a mechanical device employed, to keep the tongue under the bit (hence the expression “tongue tied”). This is also often done without first discovering and correcting the initiating cause of the behavior – usually discomfort or pain. Both cases are examples of an attempt to force horses to work “properly” in spite of an underlying problem, and in spite of communication from them that they have a legitimate complaint. Although the offending problem may or may not be directly associated with the tongue, horses commonly manipulate the highly movable tongue with any complaint in the mouth. If during such exaggerated movements the tongue is pulled back far enough, it can flop up over the bit – and quite often out the side of the mouth. Unfortunately, having the tongue over the bit makes a horse even more vulnerable to pain and injury since the bit can easily damage the much more sensitive tissues on the bottom of, and beneath, the tongue. Repeated over time this behavior can become habitual, and may persist even if the initial cause(s) have been eliminated – sometimes continuing for the lifetime of the horse. Or, it may persist because the irritating pressure or discomfort has not been corrected and continues to be a problem for the horse.

Ask A Teamster The Bit
figure 2

The Bit

The bit itself is a common cause or contributing factor of this uncomfortable dilemma. Bits with a straight, solid bar don’t allow much room for the tongue and may apply too much downward pressure on the tongue before they begin to function on the bars of the mouth. This occurs because in horses the tongue protrudes upward significantly higher than the bars (figure 1).1 The tongue tends to hold the straight bit up off the bars and it must be significantly compressed for the bit to make contact with the bars (figure 2). Naturally, some horses are more sensitive to this than others. (We should also keep in mind that some tongues are extra sensitive due to previous injuries and abuse.)

Ask A Teamster The Bit
figure 3

A solid bar bit that curves upward half moon or mullen, (figure 3) makes some horses more comfortable by providing a little more space for the tongue beneath the mouth piece. However, the effect is minimal.

Ask A Teamster The Bit
figure 4

Bits with a sliding cheek (figure 4) can be maneuvered upward by horses that learn how to do so, thus providing more room beneath for the tongue. However, in doing so, contact with the bars of the mouth may be sacrificed to some degree. Single jointed or hinged bits fold upward in the middle allowing more room for the tongue beneath, and tend to permit contact with the bars of the mouth with less pressure on the tongue (figure 5).

Ask A Teamster The Bit
figure 5

Caution: Some horse have very little upward curve to the roof of their mouth and a jointed bit may poke and injure the roof of the mouth when it folds upward under pressure – single jointed bits are not appropriate for such horses (figure 6).

Ask A Teamster The Bit
figure 6

Double jointed bits provide even more space under the bit and conform more naturally to the tongue’s upper surface while, at the same time, permitting easy contact with the bars (figure 7). They don’t fold upward acutely like the single jointed bits, and are an ideal first bit to try for horses that get their tongues over the bit to escape pressure on the tongue.

Ask A Teamster The Bit
figure 7

Diameter and surface pattern of the mouth piece are also important considerations. In general, the larger the diameter and smoother the surface, the milder the bit. A large diameter mouth piece distributes a given pressure over a greater area than a smaller diameter one does – less pounds per square inch on sensitive tissues (try carrying a loaded bucket barehanded with a large diameter handle vs. a wire bail). A smooth surface distributes a given pressure over a greater area than an irregular surface does – less pounds per square inch on sensitive tissues (try going barefoot on smooth flat surface vs. gravel). Bits with twisted or ribbed mouth pieces have irregular surfaces and are therefore more severe than comparable bits with the same diameter mouth piece that is smooth.

Severe bits and rough handling are poor substitutes for good training and driving. It is generally accepted that more problems are causes by severe bits than are solved by them.

Ask A Teamster The Bit
figure 8

In addition to fit and pressure we need to be aware that some bits can pinch the corners of the mouth. The worst offenders, in my experience, are bits with a hole drilled in each end of the mouth piece through which the bit rings pass. Skin can be pinched between the sharp edge of the hole and the ring as the ring works in the hole (figure 8). Bits with the ends of the round mouth piece bent around the bit rings, rather than the rings going through a drilled hole are less apt to pinch (figure 9A). However, if the ends are flattened where they bend around the rings, they can pinch (figure 9B). Egg butt style bits eliminate this possibility of pinching completely (figure 10).

Ask A Teamster The Bit
figure 9

It is important to select a bit for each horse that has a mouth piece which is the proper overall length for the width of the horse’s mouth. A bit that’s too short (narrow) for the horse’s mouth will crowd, pinch, irritate and hurt – especially when pressure via the lines is increased. There should be a little free space on each side between the lips/jaws and the rings, cheeks, or shanks of the bit. Extra attention must be paid to mouth piece length when fitting jointed bits. They may seem the proper length when sitting idle in the mouth, but under pressure they bend which effectively shortens their side to side length.

Ask A Teamster The Bit
figure 10

Periodically check your bits for sharp, rough or worn spots. I once had to file smooth some very sharp welds on the rings of a new bit. Wear can produce some very sharp edges. Also, metal plating can cause nasty little cuts if it begins to peel off of a bit.

If there were a perfect bit for all horses and uses, we would all be using that bit. Instead there are literally thousands of bits with different designs, purposes, sizes, weights, materials, etc. As I’ve often stated, horses are comfort lovers. If they are not comfortable, their primary goal in life is to regain their comfort. If the bit they are wearing is uncomfortable or painful, whether because of it’s design, adjustment, the way they are conformed, or due to the pressures applied by the teamster, they will not be happy horses – and they will communicate that to us. It’s to our benefit, as well as theirs, for us to heed the message and do something to help them.

Bit Adjustment

The bit is suspended from the head stall by a bit strap on either side. It may be adjusted to ride higher or lower in the horses mouth by lengthening or shortening the bit straps. Suspended too high (too tight) the bit will stretch the corners of the mouth and cause discomfort or even pain and injury. Such discomfort can be a cause of avoidance behavior with the mouth and tongue which could lead to the tongue getting over the bit. Suspended too low (too loose) the bit may clang against the tusks or corner incisor teeth in an irritating way, and many horses will fuss with a loose bit, constantly working against gravity to keep it up into position. A bit hung too low in the mouth is also easier for a horse to get it’s tongue out from under. In addition, young horses first being introduced to carrying a bit in their mouths tend to go through contortions with their mouth and tongue in an effort to avoid the unfamiliar bit. In doing so with a loosely hung bit, it is very easy for them to get their tongue out from under, and over the bit. Rather than becoming comfortable with the bit and accepting it, the youngster can quickly learn the avoidance habit of getting his tongue over the bit. Once developed this habit may last for life.

To be properly adjusted, the bit should make snug contact with the corners of the mouth without wrinkling the skin.

Please don’t misconstrue this limited discussion of considerations with respect to bits and bitting as a comprehensive or complete treatment of the subject. I’ve hardly scratched the surface of this complex and fascinating aspect of horsemanship.

Wolf Teeth

Wolf teeth are another potential source of aggravation, discom- fort, and/or pain associated with the bit, and therefore could conceivably be a factor in some horses putting their tongues over the bit. They are inconsistently present, nonfunctional, small teeth found in the upper jaw just ahead of the much larger premolars. All horses should be examined for the presence of wolf teeth before being introduced to the bit as youngsters. Any horse with an unknown status with respect to it’s wolf teeth should be examined for them. I recommend all wolf teeth be removed from horses as they are apt to cause problems with the bit sooner or later. For greater detail on wolf teeth see Ask a Teamster, SFJ, Fall, vol. 22, No. 4, page 66.

The Teamster

Whenever we attach lines to whatever bit is in a horse’s mouth and put a human on the other end of the lines we have added another very complex dynamic. Most any well adjusted bit can sit idle in a bit-savvy horse’s mouth without causing problems or avoidance behavior. However, to drive a horse we must do things with the lines that involve pressure (force) which is transferred to the horse’s mouth through a bit. Depending on how skillfully and appropriately we apply, hold, and release pressure via the lines, we may or may not give the horse reason to want (need) to escape the pressure effects we are producing in his mouth.

Since this tongue over the bit syndrome typically begins as an effort to avoid some form of pressure or discomfort associated with the bit, it is possible that this Percheron horse was subjected to problem causing pressures via the lines in the past. Often this occurs during the early training process, but depending upon the style and skill of the teamster(s) involved with a horse it can be an ongoing problem. In my opinion, it’s important to determine some things about the way the horse in your question is currently being driven. Are excessive or inappropriate pressures being used by any of the teamsters who drive him? Is pressure ever held on the horse too long before being released, or is it held constantly (steady pressure/dead hands) rather than intermittently (pressure-release)? Remember, horses are into pressure animals – the harder and steadier we pull on the lines, the harder and steadier they push on the bit. Is pressure ever applied too suddenly, erratically, or too harshly? If not corrected, these common driving errors, and others, will continue to cause aggravation and discomfort for the horse – whether or not some device is employed to physically prevent him from getting his tongue over the bit. If, on the other hand, he is being well and skillfully driven with appropriate pressures on the bit, we can proceed to consider mechanical devices that will keep the tongue safely where it belongs.

Rather than go into more driving techniques here I will refer you to Ask a Teamster, SFJ, Winter, vol. 25, No. 1, page 41.

Attempt to Eliminate The Underlying Cause(s)

I want to reemphasize the importance of discovering, if at all possible, the original underlying reasons for a horse going through the gymnastics with it’s tongue, which result in a tongue over the bit. “The reason horses retract their tongues and flop them over the bit is probably to avoid pressure and pain caused by rough or firm handling of the bit or by bits which do not leave room for their tongues… the fact is that if a horse is happy with his bit and has no fear or apprehension about having it in his mouth, he will not put his tongue over it…He will have no reason to.”2 Rather than resorting to a purely mechanical solution to this problem I feel it is imperative to first eliminate as many potential contributing factors as possible – physical problems, equipment, adjustment, and human – in an attempt to assure the horse’s comfort and piece of mind.

Ask A Teamster The Bit
figure 11

Mechanical Prevention

If, in spite of the efforts discussed above, the horse persists in putting his tongue over the bit, and we are convinced it is out of habit rather than due to ongoing inappropriate pressure or discomfort, there are some mechanical options to keep the tongue under the bit.

Some bits are especially designed to prevent horses from getting their tongues out from under and over them. They function by creating a physical extension of the bit backwards (upwards) for a great enough distance to prevent the tongue from being pulled back far enough to get out.

Ask A Teamster The Bit
figure 12

From: The Art of Taming and Educating Horses, D. Magner, 1886

“If the tongue is put over the bit (figure 11), have a piece of thin sheet-iron, about two and a half inches wide and five inches long, with the ends rounding, and the edges filed smooth. Drill two small holes near each edge, at the center, and fasten to the bit (figure 12). Shorten the cheek-pieces of the bridle, so that the bit is drawn well up in the mouth. This piece of iron renders it impossible for the horse to get the tongue over the bit. The simplest and best way of preventing this is to have the smith make a mouth-piece which is bent up, (figure 13) and comes so high in the mouth that the horse cannot get his tongue over; this works perfectly, and is not inconvenient to drive with. It should be bent up at least 2 3/4 to 3 inches, come well out to the cheek-pieces, and be filed smooth to prevent cutting or chafing the mouth.”

Ask A Teamster The Bit
figure 13


It is extremely important that such bits are designed so that the extended portion (port or plate) is not activated with leverage and rotated up against the roof of the mouth where it could cause pain and damage. On the bits shown here the lines attach to rings which cannot cause the port/plate to rotate upward when pressure is applied via the lines. However, a bit with a shank, rather than rings, could potentially rotate the port upward and endanger the roof of the mouth.

Ask A Teamster The Bit
figure 14

I have in my collection another style bit designed to operate on the same principle as those in D. Magner’s book. My stepfather/mentor, Tom Triplett inherited it from his father and passed it on to me (figure 14). Other designs are reproduced here (figure 15). It is interesting that a number of these special modifications are incorporated into or added on to straight bar bits, thus forcing the tongue to remain in place under the bit without providing more room for it, and thereby not relieving the discomfort. In view of this, the mouth piece in figure 16 may have the advantage of allowing more room for the tongue as well as preventing the tongue from getting out from under the bit.

Ask A Teamster The Bit
figure 15

Some advocate a port or plate on a separate head stall hung in the mouth independent of the bit. Not being connected to the bit, they reason, it does not interfere with, and is not affected by, the functioning of the bit, and is therefore less apt to cause problems.

Tying the tongue down to the lower jar with a strap or rag is practiced, especially in race horses where this problem seems to be prevalent. There is a fine line between tying the tongue tightly enough to prevent it’s escape, and causing circulatory, nerve, or other damage to it. It’s conceivable to me that this technique could result in aggravation or discomfort in it’s own right. I would rather use a special bit or plate as described above.

I consider a nose band that is cinched down tightly enough to potentially keep the tongue under the bit too restrictive and uncomfortable for the horse. Furthermore, I have no certainty that binding the jaws together in this way would prevent getting the tongue over the bit. It seems like trading one form of abnormal pressure or discomfort for another.

Tightening a curb or chin strap, or chain, in an effort to hold the bit down against the tongue and trap it there would be a completely unsatisfactory and inhumane technique, in my opinion. Besides being ineffectual it would magnify the very restriction and pressure that needs to be eliminated.

Final Comments

Whenever horses have a problem I feel we need to observe, research, and experiment to find a combination of equipment and techniques that will allow them to work comfortably, rather than ignoring their frustration and/or discomfort – physical, mental, emotional. Often, as in the case of the horse in question here, they do their job well in spite of a problem which makes them uncomfortable. But they are comfort lovers and they need and deserve their all important comfort.

Perhaps I should end this long winded discourse before I cause even the most avid readers to get their tongues over the bit, throw their tails up over their backs and run off.

Doc Hammill D.V.M.

Doc lives in Montana and helps people learn about horses through his writing, workshops, demonstrations, and horsemanship video series.

(1) Figures 1, 2, 3, 5, 6 and 7 depict a cross section of the lower jar at the level of the bit to illustrate various relationships between the bit, the tongue, and the bars of the mouth (jawbones and overlying gums)

(2) Behavior Problems in Horses, Susan McBane, David & Charles Inc., 1987