A survey on orthopedic injuries during a marathon sled dog race.

Purpose: This prospective observational study aimed to describe and quantify orthopedic injuries (OI) during a marathon sled dog race that led to discontinuation of racing (dropped dogs [DDs]) and to suggest potential associations with risk factors during the event.

Study Design: Prospective observational study.

Animals: A total of 989 Nordic breed endurance sled dogs that participated in the 2011 Iditarod Sled Dog Race. Data were collected via an extensive questionnaire, medical records, and speed calculations based on Global Positioning System equipment on each dog sled. OI risk factors and DD incidence were statistically analyzed on dogs and teams completing at least half the race distance, including Student's -test, Pearson's chi-squared test, Poisson regression, and various frailty analysis models as indicated. Significance was set at <0.10 for inclusion in the models with trends established at ≤0.10 and significance declared at <0.05.

Results: Questionnaire response was 40.3%. DD incidence was 38.3%, most often due to OI (50.6%). OI occurred most frequently in the thoracic limb (43.3%) compared with pelvic limb injuries (7.3%). Increased speed was associated with fewer shoulder injuries (Ratio=0.65, =0.03). Carpal injuries were positively related with increased conditioning distance (defined as training miles; Hazard ratio =1.61, =0.02). The risk to become a DD decreased with every year of increased age of the dogs (Hazard ratio =0.92, =0.03).

Conclusion: OI, specifically of the shoulder and carpus, are common in marathon sled dogs. Injury risk may be speed-related and decreases with increasing age of the dog. Further study of environmental, dietary, and trail conditions in sled dog racing orthopedic research is needed.