Preliminary study on anaesthesia and peripheral nerve block in Hair Canarian Sheep undergoing orthopaedic intervention

Abstract

Effective anaesthetic and perioperative management in small ruminants, particularly sheep, remains a challenge due to their unique physiological and behavioural characteristics. Ensuring adequate analgesia is essential to improve animal welfare and surgical outcomes. In this context, peripheral nerve blocks have emerged as a valuable technique for providing regional analgesia while minimizing systemic side effects. The aim of this preliminary study was to assess the analgesic efficacy of a combined peripheral nerve block of sciatic and saphenous nerves in Hair Canarian Sheep undergoing orthopaedic intervention, comparing the effects of two local anaesthetic agents. Five rams undergoing orthopaedic hind limb surgery underwent a peripheral nerve block, two of them receiving lidocaine 2% and three of them receiving bupivacaine 0.5% as local anaesthetic agents. The effectiveness of the peripheral nerve block was assessed using the University of Melbourne Pain Scale. During the surgical procedure, heart rate and mean arterial pressure were used as indicators of nociception. Throughout the postoperative period, pain assessment was performed based on the scoring of physiological, behavioural and biological variables. After analysing the results, it was determined that the peripheral nerve block was effective as an analgesic technique. None of the rams exhibited signs of nociception during the surgical procedure, and all of them showed final pain scores within the mild pain range, regardless of the anaesthetic agent used. Additionally, all the animals involved in this study demonstrated an adequate post-anaesthetic recovery