Application of the Ridden Horse Pain Ethogram to Elite Dressage Horses Competing in World Cup Grand Prix Competitions.

There is considerable debate about the social license to compete with horses and controversy about training methods for dressage horses. The objectives were to: 1. apply the Ridden Horse Pain Ethogram (RHpE) to dressage horses competing at elite Grand Prix level; 2. compare RHpE and judges' scores; and 3. document deviations in gaits from Fédération Equestre Internationale (FEI) guidelines. Video recordings of 147 competitors from nine World Cup competitions were assessed. Spearman's rank correlation coefficient tested the correlation between RHpE and judges' scores. The median RHpE score was 3 (IQR 1, 4; range 0, 7). There was a moderate negative correlation (Spearman rho -0.40, p < 0.001) between the RHpE scores and the judges' scores. Mouth open with separation of the teeth for ≥10 s (68%), head behind vertical ≥10° ≥10 s (67%), an intense stare for ≥5 s (30%) and repeated tail swishing (29%) were the most frequent RHpE behaviours. Deviations from FEI guidelines were most frequent in passage, piaffe, canter flying-changes, canter pirouettes and "halt-immobility-rein back five steps-collected trot". In conclusion, most horses appeared to work comfortably for the majority of the test. Further investigation of the influence of a double bridle compared with a snaffle bridle on head position and mouth opening is merited.