Fat Horses and Grazing Muzzles: Why “Giving Him a Little Break” Is a Bad Idea

You have an overweight horse, and you’ve started using a grazing muzzle any time he’s in the pasture. It seems to be working because the weight tape indicates he’s actually lost a few pounds in the last month! But you feel so sorry for him because you know he doesn’t like wearing the grazing muzzle. Should you give him a short period of free grazing each afternoon? After all, how much could he eat in a couple of hours?

The surprising answer is that he can eat an unbelievable amount in only a few hours, most likely minimizing or eliminating his rate of weight loss and possibly setting him up for colic or another digestive system upset. When researchers at North Carolina State University designed a study to check pasture intake, they found that horses with restricted grazing times were able to eat almost three times as much grass per hour as those with full-time turnout.

In the study, horses that were allowed only a few hours a day on pasture were provided with hay the rest of the time, so their avid grazing behavior should not have been motivated by intense hunger. Fresh grass is appealing to horses, and they will make the best use of abundant green forage even if hay has been available.

The most effective way to help obese horses lose weight is to restrict intake of dietary energy while gradually increasing exercise. If this program is to be effective, owners need to resist the urge to treat their horses to breaks in the schedule. This is important any time, but is especially critical during periods of lush pasture growth. Though it may seem cruel to leave that grazing muzzle on, it’s in the horse’s best interest in the long run.