Usefulness of the assessment of discharge accumulation in the lower airways and tracheal septum thickening in the differential diagnosis of recurrent airway obstruction (RAO) and inflammatory airway disease (IAD) in the horse.

The research focuses on the use of endoscopy to distinguish between recurrent airway obstruction (RAO) and inflammatory airway disease (IAD) in horses. Researchers used this method to assess the amount of discharge in the lower airways and the thickness of the tracheal septum, and concluded that this technique is effective in diagnosing these conditions.

Research Objective

• The key aim was to differentiate between two equine respiratory disorders, Recurrent Airway Obstruction (RAO) and Inflammatory Airway Disease (IAD), using endoscopic evaluation. Specifically, the study compared the amount of mucus buildup in the lower respiratory tract and the thickness of the tracheal septum.

Methodology

• The study used a sample size of 248 horses. They were divided into three categories: healthy horses (10), horses with RAO (97), and horses with IAD (141).
• Each horse underwent both clinical and endoscopic examination. Endoscopy was performed to estimate the degree of mucus accumulation in the lower 3/4 of the trachea and the tracheal bifurcation, as well as to evaluate the thickness of the tracheal septum.

Findings

• The study found that horses with RAO had a higher degree of mucus buildup in the lower airways compared to those with IAD. Furthermore, substantial thickening of the tracheal septum was noted in horses with RAO, in contrast to those identified with IAD.

Conclusions

• The findings suggest that scoring the amount of discharge in the tracheal lumen and tracheal bifurcation, as well as assessing the thickness of the tracheal septum, can be effectively employed in diagnosing RAO and IAD. Thus, endoscopic evaluation is a useful tool in the differential diagnosis of these equine respiratory diseases.