A pilot study at the University of Helsinki has revealed that pressure period inside rein tension may vary simultaneously with the ground reaction forces and in two horses, there was a high correlation between less contact time of preload force horse and keeping mouth open between strides.
Mouth Matters: Bit Pressure Related to Equine Pain and Discomfort
Researchers in this study discovered that opening their mouths while being raced is a clinical sign for pain or discomfort within the mouth for trotters. Rein TensionThe force through the reins that is being placed by the rider or driver.
Previous studies had already documented particular bit types related to moderate to severe mouth injuries in racing trotters. The theory of the investigators was that this sterner bit might reflect an issue because the lighter rein cues were not clear enough to the drivers. This led them to further explore rein tension.
They observed eight horses and riders on a racetrack at warm-up, walk, and slow trot. Outcomes included rein tension and horse behavior, with a specific emphasis on oral behaviors executed by the horses. What was surprising b/c 3 horses dyed up with moderate mouth compartments after the ride, but these horses had all been subject to greater median rein tensions (> ~ 3.5 kg per rein) compared to those that escaped injury (~2 kg per rein). Furthermore, the horses suffering from inflammation in their mouth were more likely to walk at a higher pace and for longer periods—a way of moving that suggests high arousal and is typically associated with an increased risk of mouth injuries.
Laying It Bare: The Effect of Rein Tension on Equine Behavior
They analysed five 30-second periods of the horse’s behaviour on each level of rein tension from when there was no contact to a high degree….And the results were telling.
Horses walked and kept their mouths closed mainly during low rein tension. However, under increased rein tension conditions horses mainly trotted either slowly or fast and opened their mouths for a longer period of time.
A high rein tension might force horses to show avoidance patterns, including opening their mouths — mouth opening can be interpreted as an attempt to avoid pain or discomfort in the oral cavity. In addition, the hurried walking seen in horses with moderate mouth bruises could reflect increased arousal which could further increase susceptibility to mouth injury.
The researchers concluded that horse trainers should take care to observe changes the behavior of horses’ mouths, their excitement level, and walking state. Open, repeated mouth chewing may be used in response to discomfort or pain and training requirements should be modified as necessary for the welfare of the horses.
Conclusion
This pilot study suggests that rein tension has a major effect on horse behaviour and welfare. Knowing that such a high rein tension is connected to discomfort in the horse, allows trainers and riders to overcome potentially harmful riding-methods for the equine partner. This is important information for the welfare of horses in different disciplines from racing to recreational riding as further research continues.
