Anttila Mirjami, Raekallio Marja, Valros Anna
Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland.
Department of Production Animal Medicine, Research Center for Animal Welfare, University of Helsinki, Helsinki, Finland.
Front Vet Sci. 2022 May 12;9:879048. doi: 10.3389/fvets.2022.879048. eCollection 2022.
A bit that fits is essential for horse welfare and good communication with the ridden, driven or led horses. The bit causes pressure on the sensitive structures of the horse mouth. The aim of this study was to investigate variation in oral dimensions related to bit fit in adult horses and ponies and to evaluate bit fit by comparing oral dimensions with the currently used bit size selected by the horse owner. The study population consisted of 554 horses and ponies, 308 geldings and 246 mares, age 5-29 years, presented for routine dental care. Oral dimensions: mouth width, distance between upper and lower jaw, tongue thickness and lower jaw width, were measured under sedation. Oral dimensions were compared with the most used bit mouthpiece size presented to the researcher by the owner. Bit type and material were recorded. All oral dimensions in adult horses and ponies varied by breed and sex. Mouth width and distance between upper and lower jaw correlated positively with age. Oral dimensions were significantly smaller in mares than in geldings. In coldblood Finnhorses, oral dimensions were greater than in other breeds; in ponies they were smaller. The majority of the oral dimensions correlated positively with each other. Lower jaw width did not correlate with tongue thickness. It was common to use a bit that did not fit the horse: the bit was either too short or too long (over 10 mm longer) compared to mouth width, compressed the tongue in between the upper and lower jaw, or the center link was of similar length compared to lower jaw width, thus possibly causing pressure points or a nutcracker effect on the bars of the lower jaw. Horses had, on average, space for a 14 mm thick bit without compressing the tongue. The results of this study can aid in choosing a horse bit size that fits correctly and does not cause discomfort. It is recommended that the fit of the bit is evaluated regularly as the horse ages.
合适的衔铁对于马匹的福利以及与骑乘、驾驭或牵引的马匹进行良好沟通至关重要。衔铁会对马口的敏感结构施加压力。本研究的目的是调查成年马和矮种马与衔铁适配相关的口腔尺寸变化，并通过将口腔尺寸与马主当前选择使用的衔铁尺寸进行比较来评估衔铁适配情况。研究对象包括554匹马和矮种马，其中308匹为公马，246匹为母马，年龄在5至29岁之间，因常规牙科护理前来就诊。在镇静状态下测量口腔尺寸：口宽、上下颌间距、舌厚度和下颌宽度。将口腔尺寸与马主向研究人员提供的最常用衔铁咬嘴尺寸进行比较。记录衔铁类型和材料。成年马和矮种马的所有口腔尺寸因品种和性别而异。口宽和上下颌间距与年龄呈正相关。母马的口腔尺寸明显小于公马。在冷血芬兰马中，口腔尺寸大于其他品种；在矮种马中则较小。大多数口腔尺寸相互之间呈正相关。下颌宽度与舌厚度不相关。使用不合适的衔铁很常见：与口宽相比，衔铁要么太短要么太长（长超过10毫米），会挤压上下颌之间的舌头，或者中间连接件的长度与下颌宽度相似，从而可能在下颌骨上造成压力点或产生胡桃夹效应。马匹平均有容纳14毫米厚衔铁的空间而不会挤压舌头。本研究结果有助于选择合适且不会引起不适的马用衔铁尺寸。建议随着马匹年龄增长定期评估衔铁的适配情况。
