Although horses spent more time walking when muzzled, they also more than doubled the time they spent standing. | Photo: Erica Larson

An owner’s No. 1 goal when outfitting their horse with a muzzle is usually related to weight management—either keeping them from gaining weight or helping them shed some pounds. While study results have shown that muzzles are, indeed, effective for weight control, they can also have other effects. For instance, they can alter horse behavior.

However, few studies have documented exactly how muzzling impacts behavior. So, Ashley Fowler, MS, and colleagues at the University of Kentucky, in Lexington, conducted a study to compare the behavior of 12 horses when they were muzzled and unmuzzled. She presented the results at the 2017 Equine Science Society Symposium, held May 30-June 2, in Minneapolis, Minnesota.

Fowler and colleagues observed the horses (turned out in groups of three for six hours) for one hour, two days per week, for five weeks. The researchers watched their unmuzzled behavior for the first week, then monitored their muzzled behavior for Weeks 2 through 5. The team tested closed-bottom muzzles that prevented feed ingestion, but allowed water consumption