Locomotor stereotypies and racing performance in thoroughbred horses

Among the consequences credited to locomotor stereotypies in horses is the reduction of sport performance; however, there is a lack of studies on this topic. The objective of this study was to determine if racing performance was negatively affected by weaving and stall walking in thoroughbred racehorses. Three hundred eighty-nine animals were randomly chosen from those residing at the Club Hípico de Santiago, all of which had a handicap and had run at least 5 races. The horses were divided into 2 groups according to their handicap criteria: the low performance group, with handicap from 1 to 29 (n = 333) and the high performance group, with handicap from 30 to 56 (n = 56). Handicap is an index that is assigned to all thoroughbreds that participate in turf events, according to their performance (1 = poor to 56 = excellent performance). The presence or absence of weaving and/or stall walking was observed by visual inspection of each horse. Results were expressed as percentages. Fisher's exact test was used to analyze the data, with a significance level of P < 0.05. The average prevalence of weaving was 0.77%. Weaving was 0.3% in the low-performance group and 3.57% in the high-performance group. The average prevalence of stall walking was 2.83%. Stall walking was 3.3% in the low-performance group, and there were no horses with stall walking in the high-performance group. No relationship was found between the presence of both of the locomotor stereotypies studied here and handicaps. As there is no prior scientific research on this topic, our results preliminarily suggest that weaving and/or stall walking may not have an effect on racing performance in thoroughbred racehorses and thus, no efforts should be made to avoid this display based on this reason.