A descriptive study of stress fractures in competitive event horses in the UK

The impact of stress fractures on competitive event horses in the UK is completely unknown. Ninety-one replies to 450 questionnaires sent to competitive event riders across the UK indicated that 11 horses, representing 12% of the responders, had a confirmed stress fracture. As data on the total number of horses owned or ridden by the riders were not available, the true prevalence of stress fractures in this sample of horses could not be directly assessed. Within the bounds of this study, competitive level of the rider had a significant effect on stress fracture prevalence (X2(0.05, df. 2) = 24.74, P<0.05), as did years of eventing experience (X2(0.05, df. 1) = 27.80, P<0.01). Training regime was also influential (X2(0.05,df. 1) = 26.30, PX20.01). There was a predominance of fractures in geldings (X2(0.05, df. 1) = 24.45, P<0.03); however, geldings constituted 82% of reported cases. Thoroughbred cross horses had a significantly lower incidence of stress fractures than Thoroughbreds (X2(0.05, df. 1) = 20.82, P<0.01) but constituted only 18% of the sample. Horses in the oldest age category (9–12 years) had 6% of all stress fractures (X2(0.05, df. 2) = 24.54, P<0.1). All fractures occurred on the foreleg at the knee or below, with no significant effect of anatomical location. Seventy-three per cent of horses were not competing when diagnosed (X2(0.05, df. 1) = 22.27, P<0.1). These data indicate that useful preliminary data were yielded by the questionnaire and that further research with a larger sample size is justified.