Do humans fearful of horses invoke any kind of stress response or unsafe behavior in equines?
No, according to a study carried out by researchers at the University of Guelph, in Ontario, Canada, the findings of which have been published in the Journal of Veterinary Behavior.
Katrina Merkies and her colleagues carried out an experiment to determine if horses could differentiate between a person who was fearful (psychologically stressed), another who had just exercised hard (physiologically stressed) and a calm individual who was comfortable around horses.
They said people may involuntarily emit fear or distress signals when around horses, and interpreting how horses responded was important, particularly for human safety around equines.
For the study, a total of 10 horses loose in a round pen were randomly subjected to the presence of a stationary blindfolded human in each of four treatments – the calm individual, the individual who had exercised to 70 percent of maximum heart rate and an individual frightened of horses. The fourth treatment was the control segment, in which no human was present in the round pen with the horses.
Both humans and horses wore a heart-rate monitor.
The researchers made physiological and behavioral observations of the horses, including the gait, head position relative to the withers, and their distance and orientation toward the human in the pen.
The researchers found that increasing human fearfulness was associated with a decrease in horse heart rate and the animals moved at a slower gait.
They found that the horses tended to have lower head carriage in the presence of the afraid individual and the individual who had exercised.
“Overall, horses appear less stressed in the presence of a stationary fearful or physically stressed human than a calm person,” the researchers wrote.
“Thus horses in the presence of fearful humans, particularly where participants may not be comfortable around horses, should not pose any additional risk provided normal safety precautions are employed.”
They believe it was the first study to determine if horses can differentiate between humans who were physiologically stressed from exercise as opposed to psychologically stressed from being afraid.
Preliminary results suggest an influence of psychological and physiological stress in humans on horse heart rate and behavior
Katrina Merkies, Anja Sievers, Emily Zakrajsek, Helen MacGregor, Renée Bergeron, Uta König von Borstel.
Journal of Veterinary Behavior: Clinical Applications and Research
The abstract can be read here.