Effect of a tongue-tie on upper airway mechanics during exercise followingsternothyrohyoid myectomy in clinically normal horses

Objective--To determine the effect of a tongue-tie on upper airway mechanic s in clinically normal horses exercising on a treadmill following sternothy rohyoid myectomy. Animals-6 Standardbreds. Procedure-Upper airway mechanics were measured with horses exercising on a treadmill at 5, 8, and 10 m/s 4 weeks after a sternothyrohyoid myectomy was performed. Pharyngeal and tracheal inspiratory and expiratory pressures we re measured by use of transnasal pharyngeal and tracheal catheters connecte d to differential pressure transducers. Horses were fitted with a facemask and airflow was measured by use of a pneumotachograph. Horses underwent a s tandardized exercise protocol on a treadmill at 5, 8, and 10 m/s with and w ithout a tongue-tie in a randomized cross-over design. Inspiratory and expi ratory airflow, tracheal pressure, and pharyngeal pressure were measured, a nd inspiratory and expiratory resistances were calculated. Results-We were unable to detect an effect of a tongue-tie on any of the re spiratory variables measured. Conclusions and Clinical Relevance-Results indicate that a tongue-tie does not alter upper airway mechanics following sternothyrohyoid myectomy in cli nically normal horses during exercise.