Relation between exercise-induced pulmonary hemorrhage and findings in upper airway and trachea in Thoroughbred racehorses

Abstract

This retrospective study aimed to investigate the relationship between exercise-induced pulmonary hemorrhage (EIPH) and upper airway disorders in Thoroughbred racehorses that competed at the São Paulo Jockey Club between 1999 and 2005. Data were collected from 4,036 endoscopic examinations performed 30 min after a race by the same examiner. The association between upper airway disorders and EIPH was assessed using the chi-square test. In total, 2299 and 1737 horses received and did not receive furosemide before a race, respectively. The incidence of EIPH in medicated and non-medicated horses was 52.4% and 60%, respectively. Among horses with left-sided laryngeal hemiplegia or dorsal displacement of the soft palate, 61.0% and 64.1% of them had EIPH, respectively. There was no relationship between EIPH and other upper airway disorders, such as pharyngeal lymphoid hyperplasia and mucopurulent discharge draining from guttural pouch openings. Left-sided laryngeal hemiplegia and dorsal displacement of the soft palate were positively associated with EIPH, but the association was statistically significant only for dorsal displacement of the soft palate (p < 0,05).