Nosebands can restrict horses’ natural jaw movements, often preventing them from indicating discomfort when ridden. But whether this restraint method is stressful to horses has never been proven—until now.

In a recently released study, Australian researchers revealed that horses wearing nosebands show physiological signs of stress, which increase as noseband tightness increases. What’s more, they “rebound” from their physical restrictions as soon as those nosebands come off—suggesting that welfare has been compromised.

“The horse has a lot of information to give us about how we’re riding, but it has to be allowed to open its mouth to do so,” said Paul McGreevy, BVSc, PhD, MRCVS, MACVS (Animal Welfare), professor of animal behavior and animal welfare science at the University of Sydney.

“As a community of riders, we could be a lot more thoughtful about the price our horses pay when we prevent them from moving themselves in the way they would wish,” he said