Stabling, Airway Inflammation, and Dorsal Displacement of the Soft Palate in Young Horses

Introduction Inflammatory airway disease (IAD) affects 25% to 30% of horses in training. These animals also frequently have upper airway inflammation that may predispose them to dorsal displacement of the soft palate (DDSP). The etiology of this airway inflammation remains obscure, but exposure to organic dusts may play a major role. Organic dusts originate from hay and bedding, and stabled horses can be exposed to dust levels capable of inducing airway inflammation. Using a group of young Arabian horses kept at pasture and in a stable, we asked the following questions. 1) Is stabling associated with inflammation of the upper and lower airways? 2) Do upper and lower airway inflammation occur concurrently? 3) Is a clinical mucus score correlated with the severity of neutrophilic inflammation in the lower airway? 4) Is inflammation of the upper airway associated with dorsal displacement of the soft palate?