Hva sier forskningen om bitt?


Karen L. Luke, Tina McAdie, Amanda K. Warren-Smith, Bradley P. Smith, Bit use and its relevance for rider safety, rider satisfaction and horse welfare in equestrian sport, Applied Animal Behaviour Science, Volume 259, 2023


«The study found that while most horses are ridden with a bit, horses ridden without a bit performed fewer ridden hyperreactive behaviours and had higher relative welfare scores for handling and riding (based on owners’ self-report survey data). Ridden hyperreactive behaviour, including bucking, bolting, rearing, and spooking is considered a signal of poor welfare (McLean and Christensen, 2017, Ödberg and Bouissou, 1999), so fewer ridden hyperreactive behaviours is consistent with better relative horse welfare.»


Marie Eisersiö, Jenny Yngvesson, Elke Hartmann, Agneta Egenvall, Gaping for relief? Rein tension at onset and end of oral behaviors and head movements in unridden horses, Journal of Veterinary Behavior, Volume 59, 2023


«Our results suggest that horses will open their mouth, or bite on the bit, to alleviate the oral tissues from pressure; move the head upward to avoid rein tension and move the head forward or downward to increase rein tension, likely in a presumed attempt to break free from the pressure applied.”


Mellor, D. J., Mouth Pain in Horses: Physiological Foundations, Behavioural Indices, Welfare Implications, and a Suggested Solution, Animals 2020, 10, 572


“Mouth pain in horses, specifically that caused by bits, is evaluated as a significant welfare issue […] The welfare impacts of bit-related pain include the noxiousness of the pain itself as well as likely anxiety when anticipating the pain and fear whilst experiencing it, especially if the pain is severe. In addition, particular mouth behaviours impede airflow within the air passages of the upper respiratory system, effects that, in their turn, adversely affect the air passages in the lungs […] The related components of welfare compromise therefore likely involve pain, breathlessness, anxiety, and fear.”


Cook, W. R. and Kibler, M., Behavioural assessment of pain in 66 horses, with and without a bit, Equine vet. Educ. (2019) 31 (10) 551-560


“The number of pain signals for the total population when bitted was 1575 and bit-free 208; an 87% reduction […] The welfare of 65 of 66 horses was enhanced by removing the bit; reducing negative emotions (pain) and increasing the potential to experience positive emotions (pleasure).”

Tuomola K., Mäki-Kihniä, N., Kujala-Wirth, M., Mykkänen, A. and Valros, A., Oral Lesions in the Bit Area in Finnish Trotters After a Race: Lesion Evaluation, Scoring, and Occurrence, Front. Vet. Sci. 6:206


“Of all the horses examined, 84% (219/261) had acute lesions in the bit area. In total, 21% (55/261) had mild lesions, 43% (113/261) had moderate lesions, and 20% (51/261) had severe lesions. Visible bleeding outside the mouth was observed in 2% (6/261) of the horses. Further, 5% of the horses (13/261) had blood on the bit when it was removed from the mouth, even though no blood was visible outside the mouth. In conclusion, soft tissue lesions in the bit area were common in the Finnish trotters examined. Moreover, the absence of blood outside the mouth does not rule out serious injuries inside the mouth.”


Mellor, D. J. and Beausoleil N. J., Equine Welfare during Exercise: An Evaluation of Breathing, Breathlessness and Bridles, Animals 2017


“Finally, most horses exhibit clear behavioural evidence of aversion to a bit in their mouths, varying from the bit being a mild irritant to very painful. This in itself is a significant animal welfare issue that should be addressed. A further major point is the potential for bits to disrupt the maintenance of negative pressure in the oropharynx, which apparently acts to prevent the soft palate from rising and obstructing the nasopharynx.”


Björnsdóttir et al., Bit-related lesions in Icelandic competition horses, Acta Veterinaria Scandinavica 2014, 56:40


«It was concluded that bit-related lesions in the mouth are a general problem in Icelandic competition horses. The type of bit influenced both the location and the severity of the lesions. The use of curb bits with a port was found to be a decisive risk factor for lesions on the bars of the mandible, most of which were regarded as severe. The results also raised questions about the head and neck carriage demanded for the competition horses. From an animal welfare point of view, prevention of severe lesions in the bar region of the mouth should be given the highest priority.”


Quick, J.S.; Warren-Smith, A.K. Preliminary investigation of horses’ (Equus caballus) responses to different bridles during foundation training. J. Vet. Behav. 2009, 4, 169–176

Preliminary investigations of horses’ (Equus caballus) responses to different bridles during foundation training – ScienceDirect

“Horses wearing the bitted bridle exhibited more chewing, opening of the mouth, pawing the ground, and tail swishing than those in the bitless bridle.”


Manfredi, J., Clayton, H. M. and Rosenstein, D., Radiographic study of bit position within the horse’s oral cavity, Equine and Comparative Exercise Physiology 2(3); 195–201

(PDF) Radiographic study of bit position within the horse’s oral cavity (researchgate.net)

«Riders are aware that some horses lean on the reins more than others, which has been regarded as a sign of reduced sensitivity to bit pressure. The results presented here suggest a different explanation in some cases; horses that experience discomfort due to bit pressure against the sensitive palatine tissues may learn to lean against the bit to relieve this pressure by allowing the mouthpiece to recede into the tongue.[…] Bilateral rein tension altered the position of the KK (Ultra) and JS (jointed snaffle), but had little effect on the position of the Myler bits. These differences may explain the apparent preferences of individual horses to certain types of bit, and may affect the likelihood of injury to specific oral tissues.”


Engelke, E. and Gasse, H., An anatomical study of the rostral part of the equine oral cavity with respect to position and size of a snaffle bit, Equine vet. Educ. (2003) 15 (3) 158-163


“The results of this study suggest that the age and size of the horse’s head do not provide reliable information to allow selection of an appropriate bit without prior inspection of the mouth. The main values that limit the space of the oral cavity are not influenced by age or sex, nor do they correlate strongly with parameters of the external surface of the head.”

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