Kinematics of the thoracolumbar spine while cantering in horses fitted with a saddle of three different widths

Background: A ridden horse ethogram (RHE) has been developed comprising 24 behaviours; display of ≥8 behaviours is likely to reflect musculoskeletal pain [1]. Objectives: To apply the RHE to event horses warming up for the dressage phase of a CCI 4-star three day event and compare behaviour scores with crosscountry performance. Study design: Prospective, cohort. Methods: Thirty-five consecutive horses competing on day 2 dressage were each assessed for a minimum of 10 min during trot and canter. Horses were classified subjectively as non-lame, lame or showing a stiff, stilted gait. The RHE ethogram was applied by a trained assessor. Crosscountry performance was obtained from the competition website; horses were classified as completing, eliminated or retired. Results: Twenty-seven non-lame horses scored 0-4/24 behaviours (mean and median 2/24); the most frequently observed behaviours were head behind the vertical ≥10 s; mouth open ≥10 s. Eight horses with gait abnormalities scored 3-9/24 (median 7.5; mean 6). Thirty-four horses started crosscountry. Of 28 horses which scored