According to Santa Cruz Animal Health, horse tranquilizers are used to sedate horses prior to handling, physical examination and surgical procedures. Horse tranquilizers are also referred to as equine sedatives and are suitable for ponies, foals, pregnant mares and stallions.
The most commonly used horse tranquilizer is acepromazine maleate. The medication is injected into the horse's muscle and works to suppress the central nervous system, in turn causing relaxation and drowsiness. Acepromazine maleate also promotes deep muscle relaxation, which hinders spontaneous kicking and thrusting during surgical procedures.
Adverse side effects of acepromazine maleate include respiratory distress and mild depression when administered in high doses. The depressive symptoms tend to dissipate within 24 hours.