POTENTIAL DOWNSIDE OF SEDATION DURING LAMENESS EXAMS
Although sedation can help make a lameness exam go more smoothly, a new study from Germany suggests that it might affect how the horse moves, making diagnosis more difficult.
Xylazine or other mild sedatives are sometimes administered to horses who might otherwise make lameness examinations challenging, explains Matthias Rettig, DVM, of the Free University of Berlin. “Some horses are uncooperative during a lameness exam and kick, which can be difficult and dangerous,” he says. But sedation can make a horse sluggish, so Rettig and his fellow researchers set out to determine whether it affects the biomechanical parameters that veterinarians use to diagnose and pinpoint lameness.
For the study, researchers attached inertial sensors to 44 horses who were randomly split into two groups. Baseline lameness examinations were performed on all of the horses, then half were given a low dose of the xylazine. The remaining
The data revealed that sedation had no significant effect on pelvic movement in horses with hind-limb lameness. Nor, initially, did it influence the movement of horses with forelimb lameness. However, in a few of those horses, head movement decreased 60 minutes after sedation.
The reason for the delayed effect in a short-acting sedative is unclear, says Rettig, but he offers two theories: “One reason could be that it calms the horses down and they get more used to the trotting-up-and-down procedure during the exam, which results in a reduced head movement,” he says. “Also, the analgesic effect of