At one time or another, most of us have had the experience of riding a horse that’s haunted daily by the corner of doom. 

No matter how many times he or she passes that corner of the arena, the very same corner, there is studying, side-eyeing, and—oh please not today—occasionally feet-planting, snorting, and spinning. 

Is this frustrating? Absolutely. But as a new study from the University of Florida Institute of Food and Agricultural Sciences (IFAS) suggests, it may not be entirely your horse’s fault. 

The research, funded by the National Institute of Food and Agriculture, is a collaboration between scientists and students studying equine genetics, behavior, and welfare science. The team is working to identify genes that influence a horse’s tendency to have a “startle response” to environmental stimuli (think: shadows, floating plastic bags, new objects, etc.).

The aim? One day allowing breeders to selectively breed their horses for temperament. And although the final results might still be a decade away, the initial research has already yielded some interesting findings.

In order to better understand startle responses, Samantha Brooks, an UF/IFAS associate professor of equine genetics, began by running an experiment on several groups of young horses in the UF/IFAS breeding program. The horses were hooked up to wireless heart-rate monitors and set loose in a round pen. At set intervals, Brooks’ team would open an umbrella quickly, within the animals’ line of sight. Then, the researchers analyzed their behavior and change in heart rate during and after the initial startle reaction. 

“We can’t read their minds,” said Brooks. “Their heart rate tells us what is going on inside that we cannot see from reading their body language alone. It was interesting to see the stories their heart rates told us.”

According to Brooks, one of those stories was that two clear groups of horses emerged from the data. The first was startled by the umbrella opening, had a spike in heart rate, and maintained a reactive or hyper-alert state—meaning they spent more time looking and moving away from the umbrella. 

The second group startled and experienced a spike in heart rate, but instead of a prolonged response to the umbrella like the first group, the second group calmed down quickly, and carried on with their day. In other words, these animals perceived the stimulus and found it startling, but did not go through the behavioral patterns of avoidance, fear, etc. like the first group.


“Horses have adapted over thousands of years to live with people,” Brooks said. “Some of those changes include a reduction in startle response, and [identifying that reduction is] really helpful to better [understanding] the horses we work with today.”

Blood and hair samples were taken from each horse in the study for future analysis. The team will use these samples and the data they obtained to develop subsequent studies to help differentiate the genetic components that make up how horses react to fear. 

“If we learn early on what [an] animal’s natural tendencies are most likely to be, we can make educated decisions on training and future careers, [in order] to give the horse the best shot to grow into their potential, rather than becoming a problem or danger,” Brooks explained.

The results are also expected to help researchers better understand how horses react to uncomfortable situations—information that can make a big difference in how they are handled for medical procedures, farriers, transportation, and more. “It doesn’t matter if the horse is a racehorse, therapy animal, or driving a carriage, an unplanned startle response is generally a problem,” said Brooks. 

“We are just beginning to scratch the surface of this. It might take us 10 years or more to really have a clear understanding, but it is worth the effort.”