Similar to the increase in number of marathons and ultramarathons for human athletes, equine endurance competitions in distances of 50-100 miles have become increasingly popular over the past couple of decades. The growing interest in endurance riding has encouraged participants with different levels of prior horse experience to become involved with the sport. However, if equine athletes are asked to perform over distances for which they have not been appropriately trained or if equine athletes are competed aggressively, lameness and/or fluid and electrolyte depletion leading to exhaustion might develop. When adverse ambient conditions are coupled with competition by novice riders, it becomes apparent how equine endurance athletes, in comparison to their human counterparts, could be at greater risk for development of problems during long distance competition. Unfortunately, there is a paucity of published data on completion rates for endurance rides. This type of information, including changes over time, could be useful to equine practitioners to support that endurance riding is a humane use of the horse. Thus, we collected information from the American Endurance Ride Conference (AERC) to assess completion rates and to document reasons for withdrawal from competition.

Materials and Methods

Completion rates for 50 and 100 mile endurance rides, as well as the total number of sanctioned rides, were collected from the AERC’s Annual Yearbook of Endurance Riding for 1989 through 1995. Further, results were obtained from the AERC’s Head Veterinarian’s Post-Ride Report forms for all 1996 AERC sanctioned rides. This form details the number of horses which fail to complete the competition ("pulls") and further categorizes the reasons for failure into lameness, metabolic disorders, or other problems. The latter category may include lameness and metabolic disturbances, as well as a number of other problems (lost shoe, lacerations, saddle sores, rider injury, or fatigue, etc.) for which the rider elected to remove the horse from competition, rather than be "pulled" from competition by ride veterinarians