THE TRUTH ABOUT BITS - PART 3 : ABOUT THE BARS TEETH + TONGUE...

The horse's mouth is a cavity bounded by muscle and bones. It is lined throughout with mucous membranes and contains two sets of teeth. One set is located at the front called incisors which are used for biting and snatching pasture, and the other set are called premolars and molars, which are located further back in the jaw and are used for chewing. In male horses, there are also two small canine teeth, which sit just behind the incisors. Sometimes both male and female horses can develop between one and four small seemingly 'functionless' teeth which sit in front of the premolars, although these are generally removed, because they interfere with the placement of a bit. The nerves to the mouth and teeth are supplied by the mandibular branch of the trigeminal nerve.

The space in between the canines and premolars on each side of the mouth is called a bar. This is a section of prominent bone minimally covered with tightly bound nerve rich, soft tissue called gum. Conveniently, this is the location of where the bit is placed.

The tongue is a plump, muscular organ which is highly sensitive and richly supplied with blood vessels and nerves, which send impulses to the brain, where taste is perceived. It is kept moist by the unconscious production of saliva from glands within the mouth, and is primarily used for taste and to aid chewing, swallowing and digestion. The reflex secretion of saliva occurs when there is food in the mouth, and by voluntary muscular action the tongue directs chewed food to the back of the throat for swallowing. It sits snugly within the cavity of the mouth, and any movement of the tongue moves the entire organ, which is around 30 cm in length. When a horse's mouth is closed, and when exercising, it overlaps the surface of the side teeth slightly, and in combination with the lips, aids in forming a sealed oral cavity.

DIAGRAM - BOTTOM JAW OF A HORSE

The effect of a bit on the bars, mouth, teeth, tongue and trigeminal nerve

'Nutcracker' is the well used, but little understood action of a loose ring snaffle - a commonly used bit which is termed the most gentle. This type of bit is familiar to many people, however when one observes the action of it, there is nothing gentle about it. Pressure from the reins pulls the ends of the bit downward onto the bars of the mouth, whilst driving the centre jointed section directly up into the soft, sensitive, nerve rich roof of the mouth. A restricting flash is often used to hold the mouth of the horse closed as much as possible, which ensures the action of the bit is even more painful, and also unavoidable. Often a quick hard yank of the reins, either on the ground or when mounted, is used as a discipline which not only takes the horse by surprise, and which causes an extreme amount of pain, but also destroys any possibility of maintaining a trusting relationship. Whether very little rein pressure or extreme force is applied to the bit, the mere fact that it is placed in the mouth causes widespread dysfunction in body processes, and creates discomfort, pain, short and long term diseases and injuries along with extreme psychological stress. Examples :

• Bone spurs - mandibular periostitis [common] : The bit's constant rubbing and trauma on the bars can cause the bone beneath the soft tissue of gum to grow sharp bony growths called bone spurs. Nerves in the area become damaged, and often there is tissue death with infection, odour and discharge from this area. Bone spurs are very common, and are extremely painful for the horse who uses it's mouth as a primary survival tool, and is especially painful when a bit continually rubs against these sharp protrusions


• Bruised or lacerated mouth [common] : Constant contact, banging, rubbing and sudden trauma [rider losing balance and using reins to recover, or reins being yanked as a discipline] from the bit causes bruising of the gums, bars, roof of the mouth and external corners of the mouth, as well as causing mouth ulcers, sores, lacerations, inflammation and infection


• Damage of teeth [common] : Because of constant contact and knocking of the bit on the teeth, the canines and premolars either side of the bit can start to erode and become damaged with cracks or sharp extrusions and breaks. Even with the lightest of hands, the constant banging of the bit on the teeth has an accumulative negative effect, causing nerve damage and teeth to become diseased and infected. Often to avoid bit pain, a horse clenches the bit in between it's premolars, which over time erode, crack and become infected or necrotic. When sudden trauma occurs, such as a rider using the reins to maintain balance, when falling, or a horse becoming entangled in the reins, the effect is multiplied enormously


• Fractured jaw and lacerated tongue [not as common] : Sudden trauma of a horse standing on their own reins, or riders who have lost their temper and yank the reins viciously, using the bit as a weapon with which to viciously attack the horse can cause the jaw bone to fracture or the tongue to be lacerated or even amputated. Constant damage from the actions of various types of bits which use metal twists or worse, or from bone spurs or chipped teeth can cause the tongue to become lacerated, damaged, diseased and infected which leads to necrosis and results in amputation


• Facial/trigeminal neuralgia - head shaking syndrome [common] : Facial neuralgia or trigeminal neuralgia is commonly known as the head shaking syndrome. Some examples of this are horses who almost continuously shake their head, wipe their face, flick their nose or snort. Some other common behaviours such as not liking the top of the head or ears being touched seem unrelated to nerve inflammation in the mouth caused by the bit. However the pathways of the trigeminal nerve are complex and cover the whole facial region. Pain is transferred along the various branches to seemingly unrelated locations via the inflamed and irritated nerves. The horse exhibits these behaviours to endeavour to rid itself of the sharp, severe pain which reoccurs and escalates in it's intensity. Any person who has experienced inflammation of the nerves anywhere in the body, will be able to relate to how intensely excruciating this pain can be and how even the slightest touch can cause agony and subsequently a rather violent response. Read more about this in Part 4.

Simulated bit pain exercise

As an example of the pressure in a horse's mouth and how a bit must feel to a small extent - put the head piece of a bridle over your head. Now holding your arms stretched out in front of you and your palms facing each other with thumbs pointed upwards, place the bit on your hands. Ask someone to gather the reins in their hands and exert normal 'contact' pressure. Whilst holding this firm contact, ask them to exert additional single rein pressure to simulate a turn. Again, whilst holding this firm contact, ask them to exert more pressure with both reins to simulate a halt. Now ask the person to yank the reins, when impatient with the horse, enforcing a command or when trying to regain balance, or hold a horse back from bolting. It hurts a great deal! One can only imagine the physical pain suffered by a horse when a bit is placed in the mouth, which is far more sensitive than human hands. The emotional torment of not being able to avoid or run away from this pain - of being trapped - and having to suffer whatever the rider does must be unimaginable torture.