Barrel racing horses demonstrate a high incidence of nonclinical postrace airway disorders.

Overview

• This study investigated how common airway abnormalities are in barrel racing horses after they race, and whether these issues affect their performance.
• The research found that many horses showed mild airway abnormalities, though these did not limit their run times.

Study Objective

• To determine the prevalence of airway abnormalities detected after racing in barrel racing horses.
• To examine associations between airway abnormalities and race performance (run time).

Methods

• A descriptive field study was conducted at a single barrel racing event in Oklahoma.
• Resting endoscopy (a procedure using a camera to view upper airways) was performed on 106 horses within 60 minutes after their competition.
• Endoscopic recordings were evaluated and scored for several airway disorders:
  • Pharyngeal lymphoid hyperplasia (PLH) – inflammation/enlargement of lymphoid tissue in the throat.
  • Recurrent laryngeal neuropathy (RLN) – nerve dysfunction causing partial paralysis of the larynx.
  • Dorsal displacement of the soft palate (DDSP) – abnormal position of the soft palate affecting breathing.
  • Epiglottic entrapment – a condition where the epiglottis is trapped by surrounding tissue.
  • Exercise-induced pulmonary hemorrhage (EIPH) – bleeding in the lungs during intense exercise.
• Owners completed questionnaires regarding each horse’s medical history and race run time.
• Statistical analyses included:
  • Linear regression to analyze the effects of PLH, RLN, and medications on run time.
  • Poisson regression for combined EIPH scores.
  • Logistic regression for binary outcomes of EIPH and DDSP.

Key Findings

• Abnormal airway findings were very common: 78.3% (83 out of 106 horses) showed at least one significant abnormality.
• Pharyngeal lymphoid hyperplasia was the most common abnormality, seen in 98.1% (104/106) of horses, though only 24% (25/104) of these cases were classified as severe.
• Recurrent laryngeal neuropathy was found in 61.3% (65/106) of horses.
• Exercise-induced pulmonary hemorrhage occurred in 28.3% (30/106) of horses and was positively associated with slower run times, indicating a potential impact on performance.
• The presence of PLH or RLN was not linked to changes in run time, suggesting these conditions did not affect immediate race performance.
• Use of medications did not have a significant effect on run times.

Conclusions

• Mild airway abnormalities are common in barrel racing horses post-race but generally do not limit performance.
• Subclinical (not showing obvious clinical signs) airway disorders detectable by resting endoscopy appear to be prevalent among competitive barrel racers.
• The association between exercise-induced pulmonary hemorrhage and slower run times suggests this condition may impact racing performance and warrants further attention.
• The study recommends further research using dynamic endoscopy (examining airways during exercise) to better understand airway functions during high-intensity activity and their performance implications.