Effect of combined staphylectomy and laryngotomy on upper airway mechanics in clinically normal horses.

The study’s aim was to determine the changes in upper airway mechanics in regular horses after undergoing dual procedures of staphylectomy and laryngotomy while running on a treadmill. The findings indicated an adverse effect; the dual procedure increased upper airway resistance, reduced the respiratory rate, and extended inspiratory time at all running speeds.

Research Objectives and Methodology

• This research originated from the potential need to analyze the effects of staphylectomy and laryngotomy procedures combined on upper airway mechanics in physically normal horses. These procedures are traditionally operated to address upper airway issues in horses. The research focus specifically targeted the upper airway behavior in these horses during physical activities, such as pacing or trotting on a treadmill at varying speeds.
• Six Standardbred horses were utilized to conduct the study, and intricate upper airway mechanical measurements were carried out while the horses performed physical tasks on a treadmill.
• The applied research methods involved measuring pharyngeal and tracheal inspiratory and expiratory pressure using transnasal tracheal and pharyngeal side hole catheters linked to differential pressure transducers.
• Airflow was recorded using a pneumotachograph placed at the rostral end of a completely air-tight face mask on the subjects. This measurement method was desired in the process of precisely detecting the changes in airflow in the upper respiratory tract of the horses.

Research Findings

• The results show a significant influence on upper airway mechanics in clinically normal horses that undergo combined staphylectomy and laryngotomy. The upper airway and translaryngeal inspiratory impedances were found higher at all speeds after the procedures, which indicates an increase in the airway resistance.
• Moreover, the respiratory rate dropped, and the horses’ inspiratory time lengthened at all running speeds post the dual procedures. These changes are adverse reactions as they can substantially denature the standard respiration process and physical performance of the horses.

Conclusions and Recommendations

• The study established that combined staphylectomy and laryngotomy procedures could significantly affect the upper airway mechanics in clinically normal horses and thereby exert adverse effects. For this reason, they recommend that these procedures should only be applied when they are absolutely necessary to avoid potential harm to a horse’s normal respiratory and physical performance. The study’s results contribute valuable insights on how to handle horse respiratory health, especially in performance-based or working animals.