Ulrike Dobberthien from Cavallo 3/2001 Pages 12-23 courtesy of the publisher Scholten, Stuttgart

One of the most mysterious caves in the world yawns daily against the rider: the horse's mouth. Of him is in all riding lessons the speech, but few researchers are aware of how it works.

From the outside it looks very friendly, is covered with a silky fur and soft, only two millimeters thin skin. It involves glands that produce up to 40 liters of saliva, which not only contains minerals such as sodium, but also protein, which increased to a white foam when the horse fluttered with his spit.

In the mouth is hiding a tongue that weighs between one and two pounds, is almost as long as the skull and has the densest network of nerves outside the brain, an organ that is so soft and sensitive as the lips of man.

Retracts the jaws to grab a Treat or bridle to make room, there are only really a fraction of his inner life, for example, the thin tongue tie that connects the tongue to the lower jaw. "That can tear easily," warns the Munich horses surgeon Professor Hartmut Gerhards and discourages the bad habit lead to a joke on the tongue or hold.

, The mouth closes, begins the great mysteries: What is happening in secret? The question is more than academic value. Finally, all the cavalry revolves around the fact that horses, with some exceptions, a set of teeth in your mouth now.

How they respond is most still as unknown as a black hole, even though dozens of seemingly conclusive theories in all riding styles suggest just the opposite.

One of the few cavers for foot is the Emeritus Professor Robert Cook, 71, of the University Tufs Massachusetts. The internationally recognized research scientists since the 60s. He's interested in the interactions between the mouth and teeth, and indeed already before a rider pulls on the reins.

His latest study, he completed a year ago. Over 3 years, he examined 100 horses and riders from all disciplines of therapeutic horseback riding on dressage to racing horse training. It had the horses, running, among other things, with and without teeth on treadmills while an endoscope showed what was happening in their mouths.

Cook dissected larynges, surveyed caves mouth and felt about the relationship between teeth, head posture, and trachea. His findings led him to an all-out crusade against every bite. Indulgent ridicule from colleagues ("the missionary"). He endures as steadfast as criticism of alleged profiteering

"Riders are told again and again, they should find the key to the horse's mouth," he says. "But the best key is not a key." Say no bite. Since it is hardly surprising that Cook rejects a previously brazen criterion of good riding: a horse should chew on the teeth, foaming at the mouth and have to yield to the lower jaw.

Benefits, is Cook, everything can just for the rider who does not have to then fight against a stiff neck and direct the animals easier. If a horse is working, but it should have a relatively dry mouth. "It can run either eat or not. Both go for anatomical reasons," says Cook. "All this is for the horse slobber a nuisance if it has to be deep and a lot of breathing." Any attempt to swallow the saliva carries, for the horse a hazard to get suddenly no air, an explanation for the strained expression of dressage horses snorting with wet fur, foamy mouth and gaping nostrils seemingly fiery, but in truth laborious breathing Lessons complete.

Whether it is breathed or swallowed to decide reflexes. As long as the mouth is closed, the horse breathes. If it opens its mouth, air flows into the cave. This, combined with touches of the tongue, dissolves "eat and swallow" the Reflex chain.

It rises to the rear part of the palate (soft palate). The approximately 13 cm long soft palate on the throat, like a switch, open the way to the esophagus. At the same time the epiglottis closes the trachea, the esophagus is free way to.

"A horse is a denture placed in the mouth, it receives the signal" galling, "says Cook. Along with the movements of the tongue, jaw and lips flows reflex saliva. The reflections belong to the field digestion and are controlled by the parasympathetic nervous system. Saliva on . mouth is to Cook a sure sign that the parasympathetic nervous system is activated to keep the body focuses all resources on the vital food, restricts this portion of the autonomic nervous system, heart beat and breathing, paralyzes muscles and slows the brain - by the way, the reason people why eating the urge to nap attacks.

This is precisely when riding undesirable. Finally, the horse can not digest sleepy, but move kindly; jump to race it, traverse. That only works when bringing fight or flight reflex heart and lungs, muscles and brain going. But they run through the sympathetic nervous system, the parasympathetic nervous system counterparts.

"A fast-moving horse has a dry mouth. Tongue is quietly behind the incisors, the lower jaw does not move, the swallowing reflex is turned off, the soft palate is flat on the floor of the mouth," is one of Cook.

The horse wears a bridle or curb, however, the mouth is wet due to additional feeding reflexes. The horse wants to swallow, the soft palate is raised, the horse plays with the tongue moves the lower jaw.

"By the teeth while riding the horses are neurologically by the wind," stated Cook. Because they still try to offer to the rider, as well as to obey the conflicting commands of their nervous systems, they have problems.

Every movement of the tongue and the lower jaw lifts the back of the palate and disrupts breathing. And a set of teeth in the mouth, the tongue is active, even if the rider does not feel it. The rear palate moves at high speed, even the soft palate folds up, the consequences are devastating. Finally whistles here in loading a maelstrom of 75 liters per second in the lungs, compared to four liters, the resting horse. The animal choking on your own palate and gets no air. "That's the reason why Coach of gallopers and trotters their horses on the lower jaw, the tongue tie" confirms Hans Geyer of Veterinary Anatomy at the University of Zurich. "You want to prevent any possible movement of the tongue, and thus the soft palate."

A myth, however, is that the horse is in pain is uncontrollable and goes when it sets the tongue over the bit. "Of course, the horse will hear no more attention to the tab," says Cook. "All this happened only because the reflexes or fighting will ease the pain in the mouth caused by the train at the bit."

This poses particular problems in the gallop because at this pace, breathing is coupled to the movement. With every stride, the horse makes a breath: it breathes when the hind legs on the ground and the front legs in the air, it breathes when the front legs bear the load and float back legs in the air.

What disturbs the rhythm of breathing disturbs also the rhythm of the gallop. Clock error, stiffness and trips are the result of problems that have been attributed primarily to the rider.

Even otherwise there is plenty of trouble: teeth grinding, constantly connected to the bit to play, go to the teeth, to be hard in the mouth and head banging, just to name a few, all have to do with the basic problem of teeth when the groundbreaking discovery of American Scientists considered.

"These serious problems are often associated with hypersensitivity behavior of each animal or faulty bite-application by the rider in conjunction," criticizes Cook, "but never with the fact that the method of acting on the teeth, is fundamentally wrong."

After all, are most theories of riders and not veterinarians or anatomists. Reiter contact was extensively dealt with the influence of coarse zerrender or directing careful hands, the level of training of the horse and the types of bridles and curbs. But whether and how to engage a set of teeth in the natural reflexes of the mouth, they can, so much feeling and experience they have, not judge.

What's more, horses are cooperative to own ruin. They work diligently with the bit in its mouth, whether in high school or at the Endurance and deliver peak performance.

This good nature causes horses to get sick faster. Researchers found at least 14 issues that were not previously associated with the teeth together. Accordingly dentures cause unwanted reactions of the digestive system during stress, to breath stifling neck angulation and counterproductive movements of tongue, soft palate and larynx. They cause deformities trachea and larynx pipes disrupt the coupling of breath and movement, and thus the balance and natural grace of the horse.

Dentures lead to premature fatigue, inflammatory airways disease, and they can cause lung bleeding in racehorses. Even headshaking can be caused by the bite.

"Bits are contraindicated, counterproductive and cruel," concluded Cook and thus a lively debate, which seemed far from over: Dentures versus bitless bridles. New is that consciously stand against denture is based advocates who stress a denture was just as sharp as the source. And that's the majority of riders, no matter what they come Riding, no matter how well they ride. Finally, so far was the consensus that a bite in the mouth is not a problem of principle. "A form to add yourself to the horse, not in pain," says August, sales manager of the dental manufacturer Sprenger. "On the contrary: One bite is for the horses, and for us, a piece of gum."

Even the last, according to the U.S. studies, however, in order to embitter the riding horses. Examining dead skull all breeds of horses were found namely in the closed mouth no air or space for a bit, there are no cavities;. The tongue fits snugly on the palate.

This is consistent with previously unpublished results of German scientists. At the Hannover Veterinary School, has striven the working group "Functional Anatomy" led by Professor Hagen Street, at the suggestion of Sprenger, horses mouths to measure accurately with and without teeth. It is becoming apparent that there is much less room in the mouth than previously thought, and that dentures act on the tongue and not in the store.

More precise results are however guarded like crown jewels - including in Germany, all scientific work, which should lead to a promotion or even a doctorate, is first published by the researchers involved. And that takes time.

"We know for some time" as Augsten, "that the horses mouths of warm-blooded animals are getting smaller, because the heads are fine." Reacted to it by delicate horsebit built. Sooner had the Sprinkler average bite a thickness of 23 mm, there are now only 18 mm. "A bit too thick prepares a horse with a small mouth pretty problems," said Augsten.

This knowledge goes German researchers in other parts of the world but not far enough. They call mouths, in which no metal jingles, because they consider each bite hurt the foot. "That may apply for race horses," holds against Augsten, "but a dressage horse needs a bit in order to get support.

Backing of the Head Manufacturer receives it from the official school of equitation. Is based on the FN guidelines for riding and driving with only one bite possible and therefore one of the goals on the scale of the training - but only after Rhythm, suppleness and swing.

The following without teeth is paid shall be denied, so dressage horses must be the performance audit order (LPO), even in the highest category, the Category A (tests of national importance with prize money of at least $ 1000) basically start with a bit while jumpers in the category A bitless option is allowed.

Since pushing for a suspect who is not new, but this shiny suits: A horse properly train without a bit - and let traipse not only - requires much more skill than a design with bite. Such horses were and are the business cards by experts, it is the cavesson Dancers Europe or hackamore horse trainers were altkalifornischer. These animals keep riding not only a cool head, but also a dry mouth, according to Cook, a sign of satisfaction.

But such recommendations are ignored in Germany at present.

"Cook's provocative and pushes this country with closed doors," says veterinarian Dr. Hans Dieter Lauk, one of the three editors of the veterinary specialist magazine horse medicine "Just think of the consequences that would revolutionize the horsemanship"..

Such a revolution can you look but do not like to impose on overseas researchers. For now, foaming horses continue so while experts are awaiting the results from Hannover.