Telemetric analysis of breathing pattern variability in recurrent airway obstruction (heaves)-affeeted horses

Objective—To use noninvasive respiratory inductance plethysmography (RIP) to investigate differences in breathing patterns between horses with and without recurrent airway obstruction (RAO) during the onset of airway obstruction induced through confinement to stables. Animals—12 horses with no history or clinical signs of respiratory disease (control horses) and 7 RAO-affected horses. Procedures—The study involved 2 phases. In phase 1, the optimal position of RIP bands for recording pulmonary function was investigated in 12 control horses. In phase 2, 7 RAO-affected and 7 control horses were confined to stables. Respiratory inductance plethysmography bands were applied to horses for 24 h/d to record respiratory rate and total displacement in 4-hour periods for 7 days or until RAO-affected horses developed signs of severe RAO that persisted for 2 consecutive days. Lung function was measured once daily. Results—In phase 1, thoracic and abdominal cavity displacements were best represented by RIP bands positi...