INTRODUCTION Chronic obstructive diseases of the upper respiratory tract are repeatedly encountered in horses and can significantly impede a horse's quality of life in moderate to severe cases. Typically, symptoms such as stridor or dyspnoea are caused by an obstruction or anatomic disorder of the nasopharynx or an instability of the nasopharynx or larynx (Ducharme & Cheetham, 2019; Ducharme & Rossignol, 2019). In some cases, a combination of both pathophysiologies can be observed.
