You don’t need a researcher to tell you if your horse gets stressed at competitions. You know him well enough to recognize if he’s under stress. But Danish scientists have recently decided to put stress to the test, comparing baseline cortisol (the “stress hormone”) levels at home and at a four-day national event, to get an idea of what’s really going on.

As suspected, horses' cortisol levels were higher during competition. And interestingly, they stayed elevated, compared to home cortisol levels, throughout the four days of the event.

“This indicates that the period (of the competition) was too short for habituation to occur,” said Rikke Munk Andersen, DVM, PhD, practicing clinician at Hoejgaard Hestehospital in Funen, Denmark. Andersen presented her study at the 2014 International Society for Equitation Science conference, held Aug. 6-9 in Bredsten, Denmark.

Andersen and colleagues studied 52 Danish Warmblood stallions, mares, and geldings aged three to 10 that had been selected to participate in a four-day national show. They took each horse's baseline salivary cortisol levels three times a day during the last three days of the show as well as the two days at home before the show. They also collected salivary cortisol samples just after a workout, both at home and at the show.

Cortisol levels were 44-86% higher, both for baseline and post-exercise levels, at the show than at home, Andersen said. And the levels just kept rising day after day—the opposite of what you might expect if the horses were becoming habituated to the environment.

Andersen and her colleagues also observed th