Yamamoto new scalp acupuncture method reduces pain scores and postoperative analgesic requirements in dogs undergoing orchiectomy

Background: This study evaluated the analgesic efficacy of Yamamoto new scalp acupuncture (YNSA) in dogs undergoing orchiectomy. Methods: Twenty healthy dogs were randomly assigned to the YNSA or control group (n = 10 each). YNSA was initiated 20 minutes before anaesthesia and maintained during surgery. Pain was assessed by a blinded veterinarian using the Glasgow Composite Measure Pain Scale—short form (CMPS-SF) and the Colorado State University Canine Acute Pain (CSU-CAP) scale at intervals of up to 24 hours. Salivary cortisol was measured at baseline (T0), T0.5, T2 and T24. Rescue analgesia and fentanyl use were recorded. Results: YNSA dogs returned to appetite earlier (p = 0.036) and had lower CMPS-SF scores at T0.5 (p < 0.001) and T20 (p = 0.048), and lower CSU-CAP scores at T0.5 (p < 0.001), T16, T20 and T24 (p = 0.0098). Rescue analgesia was required in one of the 10 YNSA dogs versus 10 of the 10 controls, and total fentanyl dose was 1 versus 12 (p < 0.001). Cortisol concentrations were not significantly different, although a decreasing trend was noted in the YNSA group. Limitation: This study was limited to one breed and relied on subjective pain scales. Conclusion: YNSA reduced postoperative pain and analgesic requirements, supporting its role as an adjunct in canine orchiectomy.