Evaluation of Overground Endoscopy Findings in Colombian Criollo Paso Horses.

The research explores the upper airway functional issues in Colombian Paso Horses (CPH), specifically focusing on abnormal respiratory sounds and poor performance during exercise. It was found that most horses exhibited a condition known as dynamic laryngeal collapse (DLC), which might be due to certain unique physical characteristics and workload.

Study Background and Purpose

• The study is designed to address the lack of scientific literature assessing the dynamic upper respiratory tract (URT) issues prevalent in Colombian Criollo Paso Horses (CPH). These horses are identified for their unique walking gaits that involve high flexion of the neck – a characteristic that could potentially induce upper airway problems.

Methodology and Findings

• A total of 40 CPHs exhibiting abnormal respiratory sounds and poor performance during physical exercises was examined, utilizing resting and overground endoscopy techniques.
• The data were statistically analyzed using the SciPy package, with one-tailed Fisher exact tests employed to identify any positive relationships between various upper respiratory tract disorders.
• The most common issue found was Arytenoid cartilage collapse, which was observed in 35 of the 40 cases during exercise.
• Among these, Dynamic Laryngeal Collapse (DLC) was the most significant finding. However, additional problems such as ventromedial luxation of the corniculate process apex of the arytenoid and recurrent laryngeal neuropathy were also observed.
• Only 4 out of the 40 cases showed dorsal displacement of the soft palate.

Associations and Predisposing Factors

• The study observed associations between DLC and a host of conditions such as vocal cord collapse, nasopharyngeal collapse, and medial collapse of the margins of the epiglottis. Additionally, a relationship was found between the medial collapse of the margins of the epiglottis and nasopharyngeal collapse.
• It is suggested that excessive poll flexion, small laryngeal lumen, and high workload intensity are critical predisposing factors for DLC occurrence. This condition is only typical to certain special horse breeds worldwide.
• Compared with other research, the study noted an over-representation of ventromedial luxation of the corniculate process apex of the arytenoid in the caseload. Yet, despite the intensive workload, dorsal displacement of the soft palate was relatively rare.
• The study hypothesizes that these findings could also be attributed in part to the high neck flexion performed during the horses’ special gaits.