Bits have been the go-to piece of tack for thousands of years as far as controlling and steering a ridden or driven horse. For the longest time there wasn’t much available in the way of alternatives. Now, however, horse owners or riders do have an option. Several, in fact.

Rather than acting on the mouth (mainly the lips, poll and bars) as traditional bits do, bitless bridles apply pressure to the horse’s nose, poll, face and chin groove. This may be desirable when training a young horse or working with an older horse that has had an injury or some traumatic experience related to having a bit in his mouth. It may be the only option for a horse with a facial deformity such as a severe parrot mouth or even tooth damage. And should this prove necessary, it allows a horse to eat comfortably while wearing his bridle.

Riders requiring scientific data in the bit versus bitless debate will be pleased to know that some solid information is now available. Several recent studies have shown that traditional bits can cause pain, stiffness and nervousness, and can even trigger the fight-or-flight response in horses. One study conducted by veterinarian Dr. Robert Cook of Tufts University, Massachusetts, and research partner Matthew Kibler was published in March 2018 with the title, Behavioural Assessment of Pain in 66 Horses, With and Without a Bit. Their six-year study of horses exhibiting various signs of pain when bitted, demonstrated that all but one horse showed significant reduction of pain indices when its bit was replaced by a cross-under bitless bridle. (More on these later.)

As with any tack, it’s important to find the right bitless bridle based on the type of riding you do and your personal preferences, along with your horse’s conformation, temperament and level of training. Also, regardless of which bitless bridle you choose, it’s important to give your horse time to become accustomed to it. Do some ground work, lunge him and ride quietly in an arena or small paddock before riding at speed or venturing out into wide open spaces or onto the trail.

Types of Bitless Bridles

Almost exclusively used in western riding, the bosal (from the Spanish word bozal, meaning “muzzle”), is an oval loop usually made from braided rawhide that goes around the horse’s nose and is held in place by a western headstall. It has a large heel knot, sometimes called the heel butt, at the back, behind the horse’s chin. It comes in a variety of diameters, with the largest, around 4 cm, being used on green or very sensitive horses, and smaller diameters down to just over 0.5 cm on more well-trained or less sensitive animals. Bosal reins, called the mecate, are traditionally made from a 5.4-6-metre-long rope of horse hair, and are rather prickly and stiff. They are wrapped around the heel knot, which provides weight so that when the rider touches the mecate, the horse will react promptly.

The bosal’s action causes the horse to move away from contact and toward the desired direction, speed and head position in his search for comfort. The lifting of one rein raises the heel butt slightly to one side and causes the bosal to pivot on the headstall. The effect is increased by using an indirect (neck) rein action.

Proper adjustment of the bosal is essential. For a horse with an average-sized head, it should be about 28-30 cm long and hang straight from the headstall, resting at the end of the facial bones and the start of the nasal cartilage. Higher, it won’t contact a sufficiently sensitive part of the nose. Lower, it could damage the nasal cartilage or restrict breathing. It should be loose enough to transmit rein motions to the horse, but not so loose that it swings with every movement.

The mechanical hackamore (the word “hackamore” coming again from the Spanish jaquima, meaning “halter”) has been around since at least the 1930s. It consists of a snugly fitting noseband made from leather, stiff rope or rubber-covered metal (often padded or covered with sheepskin), metal shanks and a curb chain or leather curb strap. Some have a chain or thin bar connecting the shank ends, stabilizing them and preventing them from wobbling or swiveling. The hackamore can fit on either a western or English headstall. There are several models on the market, known by such names as the Blair hackamore, the German hackamore and the Little S hackamore, but they all basically function in the same way.

The hackamore works on the principle of leverage. The noseband and the curb strap or chain surround the horse’s muzzle and produce a nutcracker action when pressure is applied to the shanks by the intermediary of the reins. The longer the shanks, the stronger the action will be. The leverage of the pivoting shanks also puts pressure on the poll. When the rider lifts the reins, the horse feels pressure and, if well-trained, he will respond before the nutcracker action comes into play. Discretion is essential, however; rough usage or a heavy hand can cause discomfort, resulting in head-tossing, balking or other resistances, and could even fracture a horse’s nose or jaw. Also, although the hackamore might give the rider great brakes, it is not well-suited for direct reining. Directional control must come mostly from the rider’s legs and seat, and the use of the indirect (neck) rein.

Like the bosal, the hackamore should be adjusted so that it rests near the end of the nasal bones, with the curb chain fitting comfortably in the chin groove. Too high, its effectiveness is reduced and the top part of the shank may rub on the cheekbone. Too low and it can restrict breathing or fracture the nasal cartilage. The curb chain should be adjusted so that it’s not too tight (one to two flat fingers) when the rider uses the reins.

The side pull is generally considered to be the mildest of the bitless bridles, basically one step up from the halter and lead rope. Most models consist of a flat or rolled leather noseband and a leather chin strap, with the reins attached to rings on either side of the noseband. To make it more severe, the top part of the noseband can be made of stiff rope with or without knots in it. Knots create pressure points on the horse’s nose.

The side pull exerts most of its pressure on the horse’s nose and the sides of his face, and may not offer sufficient control on a hot, strong or unpredictable horse. The action of the side pull is quite simple: pulling on both reins places pressure on the horse’s nose, prompting him to slow down or stop. A direct rein effect on one rein will bend or turn him in that direction. An indirect rein action can also be used. There are several models of side pull on the market, the most well-known being the Scawbrig, the Waldhausen Star and the Lindell bridles.

Most side pulls fit like a regular bridle. The noseband should lie about 4 cm from the top of the horse’s mouth. Once again, placing it too high will make it less effective, while leaving it too low might affect respiration. The chin strap should be adjusted so the horse can still open his mouth, but not so loose that it dangles.

The cross-under bridle is a newer concept, designed to provide the rider with more effective communication and lateral control than a side pull, while being more comfortable for the horse than a bosal and less forceful than a hackamore. The bridle basically hugs the horse’s head by means of a system of loops, with most models having one that passes over the poll and a second over the nose, crossing beneath the horse’s jaw. A squeeze on both reins causes the bridle to hug the whole of the horse’s head (across the poll, down the side of the face, under the jaw, and across the nose), prompting slowing down or stopping. A squeeze on one rein pushes the opposite side of the head, turning the horse in the direction of the active rein.

Proper assembly and adjustment of the cross-under bridle is essential. The chin strap should be tightened so that one flat finger can be comfortably fitted between it and the underside of the jaw. The noseband should be placed lower than a regular cavesson noseband, about 4-5 cm above the corner of the mouth. Each horse is different, however, so it might take a few trials before you find the most comfortable and effective adjustment for your horse.

There are several brands of cross-under bridles available today. The Dr. Cook design (created and endorsed by Dr. Robert Cook and used during the aforementioned study) is one of the first and most well-known, with western, English and driving models. Other bitless bridles such as the Nurtural, the Matrix, and the Rambo® Micklem® Multibridle are noteworthy as they can actually be adjusted to work as either a side pull or a cross-under bridle.