BITS are part of a system of aids used by the rider to communicate with the horse. The seat and leg aids should always precede the hand aid to achieve harmony and lightness from the horse. The effect of the bit is directly related to the type used, the level and balance of the horse and rider, condition of the horse’s teeth and conformation of the horse’s mouth.

The bars are the area in the horse’s mouth where a bit communicates pressures to the horse most effectively. These are tissue-covered sensitive cartilage on either side of the jaw between the front and back teeth (Figure 1). Between the bars, the bit lies across and presses on the horse’s tongue. Different bits may also apply pressure on the horse’s lips, roof of mouth, poll, nose and curb groove.

MOUTH CONFORMATION

The roof of the mouth/palette is a sensitive area of the horse’s mouth and can be high or low. The Irish Draught cross and Dutch Warmblood are renowned for having a large tongue so everything is nearer the palate and therefore there is less room for a bit. The Connemara has a similar problem, however the tongue is not large - the palette is lower.

It is often assumed that the thicker the bit the kinder it is to the horse but in the cases mentioned above a bit with a thicker mouthpiece could cause discomfort. Using draw reins with a single jointed snaffle causes the joint to hit the roof of the mouth which may result in resistance and behaviour issues.

In a horse with a large tongue, the bars will be protected to a certain extent from direct pressure. However, with a thin tongue there is more bar pressure from the bit. In the thoroughbred horse the tongue lies nearly on the floor of the mouth, with plenty of room between it and the roof of the mouth but the bars are more sensitive as they are narrow, sharp and thinly covered with flesh.

To assess the size of your horses tongue, gently part your horse’s lips at the side and if the tongue is bulging through the teeth, the horse has a large tongue (Figure 2). The outer edge of the tongue is more sensitive than the middle and may become ulcerated due to sharp edges on the teeth. It is important to have your horses teeth checked every six months to a year as recommended by a recognised professional.

Figure 2

BIT CATEGORIES

All bits fall into one of the following bit categories:

Snaffle

Weymouth/curb

Pelham

Gag

Bitless

SNAFFLE

A snaffle is the most commonly used bit amongst novice and experienced riders as it is gives a definite connection to the horse’s mouth. There are many different types and variations of the snaffle bit.

The Egg butt snaffle has a fixed cheek and is useful for horses that are busy or fussy in their mouths. It is not good for horses that tend to set the jaw, lean or have a dry mouth. The loose ring snaffle has much more movement and play so discourages fixing, blocking and leaning and encourages the horse to ‘salivate’ (mouth) therefore relaxing the jaw but it may pinch fleshy lips.

The Fulmer or full-cheek snaffles have cheeks on either side to aid steering and prevent the bit being pulled through the mouth. However, the mouthpieces are usually thin and therefore may not be suitable for young horses.

MOUTH PIECES

  • Single jointed bits have a lifting action against the corners of lips and pressure is also put on the sides of the tongue and on the bars due to the nutcracker action. In a double jointed bit, this action is reduced, resulting in less pressure on the bars and corners of the lips.
  • The French–link has a rounded plate which lies on the horses tongue to encourage horse to relax the jaw and mouth. The Dr Bristol has an oblong centre plate (Figure 3) which sits at an angle on the horses tongue and therefore is severe and used on strong horses.

  • The Mullen mouth is mildest of the three types of bit but can be uncomfortable if the horse has a large tongue. It is good for horses that are extremely sensitive to bar pressure but the solid mouth may give a wooden feel. Straight bars can be severe and act strongly on the edges of the tongue and underlying bars.
  • Rubber mouthpieces are soft but tend to be quite thick. Nathe bits are harder than rubber but are very flexible and of a thickness which is ideal in most situations but unfortunately they can be chewed through. Vulcanite, which is a very hard rubber, tends to be rather bulky and horses will readily lean on them.
  • The movement of rollers on a mouthpiece encourages the horse to salivate and prevents the horse from taking hold of the bit (Cherry roller). The Waterford snaffle is flexible and therefore has no nutcracker action. It can be good with an experienced rider on a strong horse who leans on or takes hold of the bit.
  • Stainless steel is the most common material used as it is hard wearing and rust-proof. Buying cheap or nickel bits are a false economy as the metals are often weaker and can develop sharp edges easily. Sweet iron and copper mouthpieces are often popular choices as they encourage horses to salivate.

    • WEYMOUTH

    The Weymouth, also known as the curb bit, is normally used with a bradoon (snaffle) as a double bridle, with two sets of reins. The first rein is connected to the bradoon and the second rein is connected to the lower ring situated on the cheek also known as the shank.

    When the bradoon rein only is in play, the action is the same as a snaffle bit. When the rein on the curb bit is used, poll pressure is caused due to the hanging cheek. The distance between the cheek ring and the mouthpiece determines the amount of poll pressure, greater difference causes more pressure. The leverage of the shanks, causes pressure on the corners of the mouth, long shanks cause more pressure.

    The curb chain is brought into play when the curb bit rein is applied and generally should be adjusted to tighten in the groove of the chin when the shanks of the bit are drawn back to 45 degrees.

    PELHAM

    The Pelham is fundamentally a bit with both a snaffle and a curb action. The Pelham exerts pressure on the poll, the curb groove and the mouth. Its action on the bars, corners of the lips, tongue depend on the type of mouthpiece used and severity of the action depend on whether two reins or rounding’s are used.

    The kimblewick is a combination of snaffle and curb but has shorter shanks than a Pelham, so therefore less leverage. A mouthpiece with a medium port has pressure over the bars but allows room for the tongue.

    Single jointed mouthpieces on a kimblewick, Pelham or hanging cheek snaffle, have a more severe squeezing action on the mouth and tongue and are likely to act on the roof of the mouth. There is minimal pressure in curb groove with jointed mouthpieces as the chain falls out of the curb groove when the mouthpiece assumes a v-shape in the mouth. The curb chain works more effectively with a mullen or ported mouth piece.

    GAGS

    Dutch gags also known as bubble bits or three-ring gags use leverage-cheeks (there is no curb chain, so no true leverage) to increase its severity. They work on the horse’s lips and poll simultaneously. These bits especially single jointed ones are severe and unkind to the horse and usually create evasions in the horse which can be difficult to correct. Horses often go above or behind the bit to avoid the severe upwards and squeezing pressure against the mouth.

    BITLESS

    Control with a bitless bridle is obtained primarily through direct pressure on the nose induced by simple leverage, a degree of poll pressure and in some cases curb action. The horse’s face is very soft and sensitive with many nerve endings. Misuse of a hackamore can not only cause pain and swelling on the nose, but extreme abuse can cause damage to the cartilage on the horse’s nose, or even break the fine bones that protect the nasal passages and cause jaw injuries.

    BIT SIZE

    The precise fit of a bit depends on the type of bit being used and the mouth conformation. For some horses the correct fit is two wrinkles in the corner of the mouth however for a horse with short lips, one wrinkle around the side of the bit may suffice. To determine the length, use a tape measure or string and measure the horse’s mouth from corner to corner. Order a bit that is 3/4 inch larger than measured so there will be enough room to avoid the bit pinching.

    Bitting a horse is not an exact science. There are many variations available that have not been mentioned above. Remember a bit is only as good as the quality of aids given by the rider. If in doubt consult a professional coach/instructor.

    Top showjumpers, Olive Clarke, Ger O'Neill and Sameh El Dahan talk about the bits that work best for them, click here to read this story.

    Marita O’Loughlin, Equine Lecturer, CAFRE Enniskillen Campus.

    Web: cafre.ac.uk