Accelerometric comparison of the locomotor pattern of horses sedated with xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride.

The research compared the movement patterns of horses sedated with different doses of xylazine hydrochloride, detomidine hydrochloride, or romifidine hydrochloride, using an accelerometric device. The study found that the sedative effects of romifidine were more prolonged, suggesting accelerometry could be a useful tool for assessing the effects of sedatives and other drugs on a horse’s movements and coordination.

Methodology

• Six healthy horses were used in the study. They were administered with saline (0.9% NaCl) solution (10 mL), xylazine diluted in saline solution (0.5 mg/kg), detomidine diluted in saline solution (0.01 mg/kg), or romifidine diluted in saline solution (0.04 mg/kg) in a random order.
• A triaxial accelerometric device was used to assess the gait of the horses before and at multiple time periods after each treatment – at 5, 15, 30, 45, 60, 75, 90, 105, and 120 minutes.
• Eight variables were calculated during these assessments including speed, stride frequency, stride length, regularity, dorsoventral power (vertical movement), propulsive power, mediolateral power (side to side movement), and total power. The force of acceleration and three components of power were then calculated.

Results

• There were significant differences in stride frequency and regularity in horses treated with saline solution and each alpha-2-adrenoceptor agonist drug.
• In speed, dorsoventral power, propulsive power, total power, and force values, significant differences were observed between treatments with saline solution and detomidine or romifidine.
• There was a significant difference in mediolateral power between treatments with saline solution and detomidine.
• No significant difference was found in the stride length between treatments.

Conclusions

• The study concluded that the accelerometric evaluation of horses administered with alpha-2-adrenoceptor agonist drugs showed more prolonged sedative effects of romifidine compared to xylazine or detomidine.
• Accelerometry could be useful for assessing the effects of other sedatives and analgesics. These data could aid in drug selection, especially in situations where a horse’s balance and coordination are critical.