Study of laryngopharyngeal pathology in Thoroughbred horses in southern California.

This research seeks to determine the prevalence and pathology of laryngopharyngeal abnormalities, especially subepiglottic ulcers, in Thoroughbred racehorses from Southern California. It also assesses their potential impact on the horses’ racing performance, indicating more study needed for accurate diagnosis and treatment implications.

Research Methodology and Objective

• The main aim of this study was to ascertain the prevalence and structural examination of laryngopharyngeal lesions, with a particular focus on subepiglottic region and, most specifically, subepiglottic ulcers.
• 91 Thoroughbred racehorses, received for post-mortem examinations from four major Southern California racetracks, were dead due to different reasons like catastrophic musculoskeletal injury, sudden death, laminitis, colic, colitis, neurological disorders, pleuropneumonia, and arytenoid chondropathy.
• The researchers collected laryngopharyngeal specimens and evaluated them grossly. They also performed histopathology on selected cases.

Results of the Study

• 13 horses (14.3%) had at least one type of laryngopharyngeal abnormality.
• 7 horses (7.7%) showed lesions in the subepiglottic soft tissues. Among them, researchers found four subepiglottic ulcers, two soft palate ‘kissing lesions,’ and one ‘subepiglottic scar.’
• 8 horses (8.8%) had lesions in other parts of the laryngopharynx, such as mucosal ulcerations, arytenoid chondropathy, epiglottic entrapment, and partial absence of arytenoid cartilage.

Conclusions and Implications

• The research revealed that subepiglottic area lesions are prevalent, suggesting that vital laryngopharyngeal abnormalities might often be overlooked during routine endoscopy of the standing horse. Such procedures often neglect the examination of the subepiglottic tissues.
• The subepiglottic ulcers were chronic-active and featured viable hyperplastic epithelial margins, suggesting that with proper treatment, healing and re-epithelialisation could occur.
• The observed lesions don’t necessarily indicate a clinical problem. More comprehensive prevalence studies and correlation between identified abnormalities and performance is required to accurately determine the clinical significance of subepiglottic soft tissue lesions.