When behavioral problems arise with riding horses, owners undoubtedly will search for solutions. But many horse owners don’t think to look their horse in the mouth for an answer. According to recent study results, the bit could be the cause of more behavioral problems and ailments than many owners currently recognize.

W. Robert Cook, FRCVS, PhD, completed a study recently in which he compared 66 domestic horse skulls and 12 wild horse skulls in four U.S. Natural History Museum collections for differences in structure near the point where the bit contacts the skull.

A five-point grading scale was used to document bit-induced bone spurs on the bars of the mouth (grade 1 being normal and grade 5 the most abnormal). Bone spurs are outgrowths on the bars of the mouth, akin to splints on the cannon bone. The first cheek teeth in the lower jaw are the first to be damaged due to their close proximity to the bit, so the frequency of dental damage was based on these.

Key findings of the study included:

  • 62% of the domestic horse skulls had bone spurs on the bars of the mouth;
  • 61% of the domestic horse skulls exhibited erosion of the first lower cheek tooth;
  • 88% of the domestic horse skulls showed evidence of either bone or dental damage;
  • As the grade of bone spur formation increased from 1 to 5, so did the frequency of dental damage; and
  • No bone spurs or dental damage was found in any of the 12 wild horses skulls.

Cook suggests that if behavioral problems arise in riding horses, owners and trainers should consider the bit as a cause along with other possibilities. He added th