Type, prevalence, and risk factors for the development of orthopedic injuries in endurance horses during training and competition

OBJECTIVE: To report the type, prevalence, and risk factors for the development of orthopedic injuries in endurance horses. ANIMALS: 235 endurance horses. PROCEDURES: Medical records of horses examined between January 2007 and December 2018 were reviewed. Recorded data were birth; breed; sex; dates of first and last examinations; presence of any conformation fault, lameness, positive flexion test result, and orthopedic injury; starts in endurance competitions; level of athletic activity; professional status of trainer or rider; and whether an orthopedic injury developed in > 1 limb or during or within 2 days after competition, lameness resolved after treatment, reinjury occurred, horse was eliminated from competition after treatment, and the horse required retirement from endurance competitions. Anatomic locations of injuries were classified as proximal portion of the metacarpal area, midportion of the metacarpal area, metacarpo- or metatarsophalangeal (fetlock) area, tarsus, or foot. For each outcome, multivariable logistic regression models were developed after bivariable logistic regression and collinearity analyses. RESULTS: 351 orthopedic injuries were detected in 76.6% of the horses, with 27.1% that affected the fetlock area, 21.4% the proximal portion of the metacarpal area, 21.1% the foot, 12.8% the tarsus, 9.1% the midportion of the metacarpal area, and 8.5% other sites. High suspensory disease (21.4%) was the most common condition, followed by arthropathy of the metacarpo- or metatarsophalangeal joint (19.4%) and solar pain (14%). Age at first examination (OR, 1.70; 95% CI, 1.37 to 2.11), months of observation (OR, 1.03; 95% CI, 1.01 to 1.05), conformation fault of forelimbs (OR, 4.08; 95% CI, 1.53 to 10.89), and amateur status (OR, 2.62; 95% CI, 1.86 to 7.99) remained significant in the final multivariable regression model for the development of orthopedic injuries. CONCLUSIONS AND CLINICAL RELEVANCE: A large number of endurance horses developed ≥ 1 orthopedic injury during training or competition. Clinical and diagnostic examinations should be focused with particular attention to the metacarpophalangeal joints, proximal portion of the metacarpal area, and foot.