Pharmacopuncture with low-dose dexmedetomidine and saline aquapuncture at acupoint Governing Vessel 24 provides sedation in healthy adult horses.

Overview

• This study investigated the effectiveness of delivering the sedative drug dexmedetomidine via pharmacopuncture at a specific acupoint (GV-24) in horses, comparing it to traditional intravenous (IV), subcutaneous (SC) routes and saline aquapuncture at the same acupoint.
• The findings showed that sedation levels from dexmedetomidine pharmacopuncture at GV-24 were similar to those achieved through IV, SC administration, or saline injection at GV-24, suggesting this method is a viable alternative for horse sedation.

Introduction and Objective

• Pharmacopuncture refers to injecting drugs into acupuncture points to achieve therapeutic effects.
• Dexmedetomidine is a sedative commonly used in veterinary medicine.
• Governing Vessel 24 (GV-24) is an acupoint located on the horse thought to be influential in sedation.
• The study aimed to compare sedation effects from:
  • Dexmedetomidine at GV-24 (pharmacopuncture)
  • Saline at GV-24 (aquapuncture control)
  • Dexmedetomidine administered subcutaneously (SC) on the lateral neck
  • Dexmedetomidine administered intravenously (IV)
• The hypothesis was whether pharmacopuncture could provide sedation comparable to traditional routes or aquapuncture alone.

Methods

• Subjects: 10 healthy adult mares participated in the study.
• Design: Blinded, randomized, crossover with each horse receiving all four treatments spaced to avoid carryover effects.
• Treatments:
  • Dexmedetomidine at GV-24 (1 μg/kg)
  • Saline at GV-24 (1.5 mL)
  • Dexmedetomidine SC on lateral neck (1 μg/kg)
  • Dexmedetomidine IV (1 μg/kg)
• Measurements were taken baseline and at 5, 15, 30, 45, 60, and 90 minutes post-treatment:
  • Facial sedation score (FaceSed)
  • Equine sedation score (EquiSed)
  • Head height above ground (indicator of sedation)
  • Pulse rate and respiratory rate
• Statistical analysis used pairwise Wilcoxon signed rank tests to compare sedation parameters between treatments and from baseline within each treatment.

Results

• No significant difference in sedation scores between any treatment groups at measured time points.
• Changes from baseline sedation scores:
  • FaceSed scores increased significantly in:
    • DexmedGV24 (all time points)
    • SalineGV24 (all time points)
    • DexmedSC (some later time points: 15, 30, 60, 90 min)
    • DexmedIV (early to mid time points: 5 to 60 min)
  • EquiSed scores increased significantly at various times, differing per group but consistent with sedation timing.
  • Head height, a physical indicator of sedation, lowered significantly:
    • At 60 min post DexmedGV24
    • At multiple time points (5, 30, 45, 60 min) post DexmedIV

Discussion and Conclusions

• Pharmacopuncture delivering low-dose dexmedetomidine at GV-24 provided sedation comparable to traditional IV and SC administration.
• Saline injection at GV-24 also induced some sedation, indicating possible placebo effects or stimulation from aquapuncture itself.
• These findings suggest that pharmacopuncture at acupoint GV-24 is an effective alternative sedation method in horses.
• This method may offer benefits such as localized treatment and potential reduction in systemic drug doses.
• Further studies could investigate mechanisms of sedation via aquapuncture and pharmacopuncture and optimize dosing regimens.