Do horses lose their responsiveness to cues when exposed to multiple riders and handlers?
Researchers had expected that responsiveness to acceleration and deceleration cues would decline with an increase in the number of riders. Their hypothesis proved partly correct.
Jessica McKenzie and her fellow researchers, reporting in the open-access journal Animals, found that as the number of riders or handlers increased, horses became more difficult to accelerate and less difficult to decelerate.
“This could indicate that an increase in rider or handler numbers is associated with those horses becoming relatively more unresponsive to leg and whip cues than to rein cues,” the University of Sydney study team reported.
The researchers said successful horse training depended on riders giving clear and consistent cues.
“When cues are inconsistent, the horse may become confused, frustrated, or unresponsive.
“It is likely that each rider or horse trainer differs in the way they deliver training cues because humans vary in their weight, height, riding style, handedness, experience, and skill level.”
“When training cues are inconsistent, we expect to see a decrease in trained responses or an increase in conflict behaviours.
“Either of these outcomes could lead to an increased risk of injury to the rider as well as exposing the horse to negative welfare outcomes.”
McKenzie and her colleagues said there were many situations in which horses may be exposed to multiple riders or handlers.
“Privately owned horses may be primarily ridden or handled by their owners but also by coaches, trainers, friends and family.
“Horses kept in professional training stables or agistment or livery centres would commonly be handled and sometimes ridden by grooms and other staff.”
Routine husbandry procedures, such as farriery and dentistry, may also require the horse to be handled by unfamiliar humans.
Horses in riding school or trail riding establishments are typically exposed to several riders, often including novice riders. Novice riders differ from experienced riders in their posture, synchronicity and balance.
“These differences could inhibit the novice rider’s ability to deliver clear signals and a timely release or reward.” However, studies have reported no effect of rider experience level on ridden horse behaviour or biological markers of stress.
The researchers based their findings on data supplied in relation to 1819 horses through the Equine Behavior Assessment and Research Questionnaire (E-BARQ), an ongoing online global survey of horse owners and caregivers.
They analysed the responses to learn more about the relationship between acceleration, deceleration, and responsiveness to the number of riders.
“In the current study, horses with multiple riders were more likely to be unresponsive to leg and whip cues, compared to horses with fewer riders.
“This infers that these horses may have been exposed to incorrect application of leg or whip cues.
“This,” they said, “could lead to a downward welfare spiral, as riders or trainers may resort to using stronger pressure or punishment techniques when a horse is seen as unresponsive.
“This escalation of pressure can also be achieved with equipment changes, for example by adding spurs or a whip to reinforce leg cues. The escalation of pressure could cause an already-confused horse to become withdrawn, or to react in explosive and unpredictable ways.”
The authors said a horse with a good deceleration response could also be perceived as a safe horse for beginner riders.
“Therefore, the results could indicate that horses with multiple riders, such as those used for lessons in a riding school, are selected for this quality.
“However, if this were the case, we would expect to see similar results for horses with beginner riders, as the same horse-rider matching considerations would apply.” This was not the case.
Riders who described themselves as beginners produced results closer to the researchers’ original prediction of being less responsive to both acceleration and deceleration cues, and less responsive to rein pressure, than more experienced riders.
“This could indicate beginner riders cause the horse to become less responsive to training cues in general.”
It is likely that horses regularly ridden by beginner riders become less responsive to cues due to rider error, the authors said.
“For example, the horse may become habituated to unrelenting rein pressure, or the rein signal could be overshadowed by a tightly gripping leg that applies contradictory acceleration cues.”
The study team also found that horses became easier to accelerate, easier to decelerate and more responsive to rein signals as they aged.
“This,” they said, “likely reflects the effect of training and experience as the horse progresses through its ridden career.”
However, consideration should also be given to the possibility that poorly responding horses may have been culled, they said.
Mares were more responsive to rein cues than geldings initially, but this effect diminished with age. This could reflect the potential for mares to be used in breeding, which may cause some mares to have breaks in their training.
Breed also had an effect. Standardbreds were more difficult to accelerate and less difficult to decelerate than crossbred horses. Heavy horses, Iberians, ponies, Warmbloods, and Quarter Horses were all less difficult to decelerate than crossbred horses. Heavy horses were also more responsive to rein cues than crossbred horses.
They noted that Standardbred horses would not have been trained to respond to leg pressure at the start of their careers. “This could have an effect that would not necessarily relate to temperament.”
The study team said their findings suggest that horses’ responses to rein tension cues are more persistent than their responses to leg pressure or whip cues.
“Alternatively, horses with these responses may be actively selected for multiple rider roles. Longitudinal studies of this sort should reveal how the number of riders or handlers affects horse behaviour and could lead to safer and more humane equestrian practices.”
The University of Sydney study team comprised McKenzie, Kate Fenner, Michelle Hyde, Ashley Anzulewicz, Bibiana Burattini, Nicole Romness, Bethany Wilson and Paul McGreevy.
McKenzie, J.; Fenner, K.; Hyde, M.; Anzulewicz, A.; Burattini, B.; Romness, N.; Wilson, B.; McGreevy, P. Equine Responses to Acceleration and Deceleration Cues May Reflect Their Exposure to Multiple Riders. Animals 2021, 11, 66.