Association of increased tracheal mucus accumulation with poor willingness to perform in show-jumpers and dressage horses.

This study investigates the relation between physical conditions like pharyngeal lymphoid hyperplasia, recurrent laryngeal neuropathy, mucus accumulation and sports performance, specifically willingness to perform, in horses. It found that an increased level of mucus accumulation appears to be linked with a decreased willingness to perform among sport horses.

Study Objective

• The purpose of this study was to explore the impact of many physical conditions – pharyngeal lymphoid hyperplasia (PLH), recurrent laryngeal neuropathy (RLN), mucus accumulation (MA), and tracheobronchial secretion neutrophil percentage (TBS-N) – on the performance of sport horses, specifically their willingness to perform.

Study Approach

• The researchers used airway endoscopy scores, tracheobronchial secretion cytology, and rider-assessed general impression and willingness to perform as a method of investigation.
• The study was performed on 171 top-level sport horses.

Main Findings

• The study found that increased mucus accumulation appears to be linked with poor willingness to perform in sport horses.
• It was observed that older horses had decreased PLH scores and increased TBS-N.”,
• Mucus accumulation scores of 3 or higher were found to increase the odds of the horse having poor rather than excellent willingness to perform.
• Compared to a TBS-N of below 20%, a TBS-N of 20-50% was associated with decreased odds of poor rather than excellent willingness to perform.

Additional findings

• The research also found that horses with an RLN grade of 2 or higher had significantly higher odds of giving a poorer general impression and willingness to perform.
• This finding, however, is cautioned against by the researchers due to the fact that only two horses had significant RLN (grade of 3 or higher).