Position of different snaffle bits inside the equine oral cavity

Zur Lage unterschiedlicher Trensengebisse im Pferdemaul

Engelke E, Gasse H

DOI: 10.21836/PEM20020405
Year: 2002
Volume: 18
Issue: 4
Pages: 367-372

The position of snaffle bits of different types and their areas of contact to the oral mucosa in 31 horse heads were investigated by means of palpation and radiology. This study also included simulated tightening of the reins in order to describe the resulting changes of the snaffle bit position.With no tightening of the reins the snaffle bit was in contact with the palatal mucous membrane only if the bit was too thick in relation to the size of the mouth. The contact areas varied, depending on the type of the snaffle bit (single-jointed or double-jointed). Simulated tightening of the reins - directed at an angle of approximately 50° to the bridge of the nose - caused all types of snaffle bits (1) to relocate caudally, (2) to press on the dorsal surface of the tongue and (3) to rotate on their own axes.Radiology alone was not sufficient to determine the distance between the snaffle bit and the oral mucosa. In addition it was necessary to inspect and palpate the oral cavity. However, the X-ray images were excellent for demonstrating the changes in the position of the bit when the reins were tightened. The results are discussed with reference to some reports in the literature about bit-related injuries.It was concluded that the choice of an adequate bit depends on a thorough examination of the individual horse. The width and – especially – the thickness of the bit are relevant parameters which make the bit “comfortable” for the horse, whereas bits of inappropriate size can cause a higher risk of injuries.