Horse Illustrated Magazine

Last spring, Equine Canada, the national governing body of equestrian sport for Canada, implemented a rule requiring approved protective helmets for dressage riders competing at Fourth Level and below and in certain young horse and equitation tests.
As of Jan. 1, 2012, Canada has expanded this rule to include all riders at Equine Canada sanctioned shows. The rule now states:

All riders, regardless of age or level or competition, must wear ASTM/SEI or BSI/BS EN approved protective headgear at all times when mounted at any EC-sanctioned Dressage competition at the event location.

The rule was decided after Dressage Canada solicited feedback on the topic from its membership. Most members were thoroughly in favor of helmet use during competition.
“I am very proud of our Dressage Committee for taking this step,” said Equine Canada president Michael Gallagher. “I believe we are the first national federation in the world to introduce this rule across all levels, and I can guarantee we will not be the last.”

Currently, the United States requires helmets for all dressage riders at United States Equestrian Federation competitions except for adult riders mounted on horses competing only at FEI levels.