Previous studies evaluating the behavioral responses of horses to different types of bridles found that horses perform at least as well, if not better, with a bitless bridle than a jointed snaffle.
To probe deeper into the issue, Robert Cook, FRCVS, PhD, and Daniel Mills, BVSc, PhD, IL TM, CBiol MIBiol, MRCVS, tested their hypothesis that a horse’s behavior would change--for the better--when ridden with a bitless bridle, compared to a bridle with a bit. (Cook developed and patented the cross-under Bitless Bridle in the United States.)
Four riding school horses, none of which had ever been ridden in a crossunder bitless bridle, were included in the study. The four riders were Certified Horsemanship Association riding instructors and the judge was a CHA Master Clinic Instructor, a Centered Riding Instructor, and a member of the American Judging Association, with 25 years experience. The test was performed during the Certified Horsemanship Association’s International Conference at the Kentucky Horse Park in 2008.
Horses and riders completed a four-minute, 27-phase exercise test first with a bitted then bitless bridle. Each phase was judged using a 10-point scale.
According to Cook and Mills, "Mean score, when bitted, was 37%; and through the first four minutes of being bitless, 64%."
"For the sake of both equine and human welfare a crossunder bitless option is recommended," the authors stated. "Equine organizations that currently mandate use of the bit for competitions are urged to review their rules."
Details regarding the study, "Preliminary study of jointed snaffle vs. crossunder bitless bridles: Quantified comparison of behaviour in four horses," will be published in an upcoming edition of the Equine Veterinary Journal. The abstract is available online.
Disclaimer: Seek the advice of a qualified veterinarian before proceeding with any diagnosis, treatment, or therapy.