Stable ventilation is the single most important environmental management factor for horses with asthma (recurrent airway obstruction), yet is consistently underinvested in equine housing design.
Poor stable ventilation is one of the most common and consequential housing welfare problems for horses, directly causing or exacerbating respiratory disease that affects up to 14% of the equine population. The desire to keep horses warm — particularly in cold climates — frequently overrides appropriate ventilation, creating enclosed, humid, dusty environments that are directly harmful to respiratory health. The welfare solution requires accepting some environmental temperature variation in exchange for air quality that does not chronically challenge respiratory function. This trade-off strongly favors ventilation in any honest welfare analysis.