“…High dust concentrations are common in the environment of conventional stables43, 45, 46, 47, 48 and several studies have identified stabling of horses as a risk factor for IAD 28, 49, 50, 51. Within this environment, the respirable fraction can contain a variety of organic and inorganic particles including fungi, molds, endotoxin, beta‐D‐glucan, ultrafine particles (<100 nm in diameter), microorganisms, mite debris, vegetative material, inorganic dusts, and noxious gases 42, 45, 49, 52, 53…”