Gait analysis using 3D accelerometry in horses sedated with xylazine

The aim of the present study was to verify the efficacy and sensitivity of an accelerometric device in detecting and quantifying the degree of movement alteration produced in horses sedated with xylazine. Horses (n = 6) were randomly administered either xylazine or a control by intravenous injection, with at least 1 week between each treatment. A triaxial accelerometric device was used for the accelerometric gait assessment 15 min before (baseline) and 5, 15, 30, 45, 60, 75, 90, 105 and 120 min after each treatment. Eight different accelerometric parameters were calculated, including speed, stride frequency, stride length, regularity, dorsoventral power, propulsion power, mediolateral power and total power, with the force of acceleration and the dorsoventral, mediolateral and craniocaudal (propulsive) parts of the power then calculated. Administration of xylazine decreased many of the parameters investigated, with significant differences for speed, stride frequency, dorsoventral power, propulsion power and total power at 5, 15, 30 and 45 min after injection. There were no significant differences in stride length values at any time point. Decreases in regularity values were evident with significant differences at every time point from 5 to 120 min following xylazine injection. Force values were also significantly reduced from 5 to 30 min after treatment and a redistribution of the total power was observed 5 min after injection as the mediolateral power increased significantly, while the dorsoventral power decreased. Accelerometry offers a practical, accurate, easy to use, portable and low cost method of objectively monitoring gait abnormalities at the walk in horses after sedation with xylazine. (C) 2011 Elsevier Ltd. All rights reserved.