Most horses in the U.S. have some degree of asthma and nearly 15 percent have a severe case. But now, thanks to collaboration between a medical school and a veterinary college, a specially designed equine respirator may help these horses while cutting down on their medications.

Although human respirators cover the mouth and nose, a horse needs its mouth free to graze and drink. After considering many approaches, researchers eventually designed a respirator that covers only a horse’s nose by snuggly fitting on its bridle. A flexible silicone seal keeps it in place, and a foam filter reduces the amount of dust the horse inhales.

Most horses get used to wearing the respirator all the time. That’s important, since they’re constantly exposed to particulate irritants in hay.