A fearful horse, in the wrong hands, is a dangerous horse.

That’s why Danish researchers have set out to determine clues to identify the foals that are likely to become fearful adults.

As a result, those horses could go to the right trainers with the skills necessary for dealing with fearful horses and reducing the risk of accidents.

And ideally, they could stay out of the breeding shed, according to Janne Winther Christensen, PhD, of Aarhus University, in Tjele, Denmark.

“A main cause of accidents is horses’ fear reactions,” Winther Christensen said, citing previous studies.

“As prey animals, there will always be situations where a horse can become frightened, but we can change the threshold for when this happens—through selection against fearfulness and appropriate habituation methods—and we can train them not to escape when the threshold is reached through appropriate knowledge and use of learning theory.

“Everyone involved in horse breeding, horse sports, and education of riders and horses has a shared responsibility to help reduce horse-human accidents,” she said. “Further, it is unethical to breed fearful animals due to well-studied, negative effects on animal welfare.”

But studying the development and consistency of fearfulness isn’t easy, according to Winther Christensen. It requires studying the same group of horses in exactly the same management situation for the first three to four years of life—which is rare in the horse world.

“If a group of foals are tested and then some are sold to leisure riders and kept in group housing, others are trained by professional riders and perhaps kept 23 h a day in a stable, it will be difficult to interpret adult test responses because they can be affected by individual experiences,” she said.

Determined to carry out such a longitudinal study—and motivated by the high rate of horse-human accidents related to the horse’s fear reactions, as exposed in this new Danish website tracking such accidents—Winther Christensen and her team followed 25 Warmblood stallions from ages five months (before weaning from the dam) to three and half years, in identical conditions.

All 25 stallions, belonging to the same stud farm, stayed together as a group (at first, with their dams) throughout the entire study period, with limited human handling.

They found that, as pre-weaned foals, the horses showed distinct differences among each other when faced with an object they’d never seen before—namely, plastic sheets spread out on the ground with colourful plastic boxes at each corner. (The foals didn’t have to actually walk over the plastic, but could go around it.)

The scientists observed how long it took for the foals to get back to their dams—who were waiting on the other side of the “scary object”—and what the foals did during that time.

The nervous ones showed alertness and “hurried” back to their mothers, whereas the less fearful ones approached and investigated the objects.

Heart rate monitors confirmed that the “nervous” foals had higher heart rates than the “calm” foals, Winther Christensen said.

As yearlings and as three-year-olds, the horses had to pass different scary objects, like a colourful plastic ball set on a colourful plastic waste basket, in order to get to a bucket of food.

The ones who were nervous as weanlings were also nervous as yearlings and adults, with higher heart rates and longer durations of alertness. The calmer ones continued to have lower heart rates compared to the nervous ones, and showed more object sniffing and touching.

Overall, the foals that showed more alertness towards objects were also the ones who later showed more pronounced fear reactions.

“Our study shows that fearfulness is consistent across age from foal to adult, and this knowledge is useful for selection purposes, as well as for ensuring appropriate training and handling of the most fearful individuals,” she explained.

“If breeders were willing to select for less fearful horses, only calm horses should be used for breeding,” she said.

“Selection experiments in other species have shown that after a few generations, the population will generally become less fearful.

“In horses, genetic selection would be further enhanced through maternal transmission of calm behaviour, due to the long period of close maternal contact.

“However, identifying the fearful horses at an early age would also be very beneficial for these horses as well as for human safety,” she continued.

“Fearful horses require skilled trainers, more training, and patience. They can still become good riding horses, but they can be dangerous in the hands of unskilled riders.”

Study highlights

  • Researchers investigated the development and consistency of fear responses in horses.
  • Twenty-five warmblood stallions were tested at 5 months, 1 year and at 3.5 years.
  • Some changes in fear-related behaviour were evident pre and post weaning.
  • Foals’ expression of alertness was the best predictor of their later behavior.
  • Responses were consistent between tests conducted at 1 and 3.5 years.

The study titled: Development and consistency of fearfulness in horses from foal to adult by Janne Winther-Christensen, Carina Beblein and JensMalmkvist is published in Applied Animal Behavior Science and the abstract found here.