We investigated the risk factors for epistaxis in Japanese flat races over a 20-year period. The veterinary records of horses identified as having epistaxis by endoscopy on the race day, and the official racing records of all flat races from April to September between 2001 and 2020, were reviewed. The racecourses (n = 10), surface type, surface condition, race class, race distance, race year, sex, age, two training centers, ambient temperature, and body weight on race days were assessed using multivariable logistic regression (p p p < 0.001, especially Sapporo [OR; 4.74, 95% CI, 3.07–7.31], Hakodate [OR, 4.66; 95% CI, 3.05–7.11], and Kokura [OR, 4.14; 95% CI, 2.65–6.48] compared to the reference racecourse [Kyoto]). These results can facilitate developing interventions to reduce epistaxis in flat racing.
