Practical anaesthesia and analgesia for surgical castration and dehorning of extensively managed beef cattle

Castration and dehorning are routine husbandry procedures commonly performed on cattle within the beef industry. Although there is extensive literature demonstrating the pain and distress resulting from these procedures, they have traditionally been performed without anaesthesia or analgesia due to the practical constraints associated with administering injections on-farm. There are currently no alternative options to performing castration and dehorning, therefore there is a need to incorporate pain relief into routine procedure. Recently, the practical constraints associated with conventional forms of anaesthesia and analgesia have been addressed through the development and registration of ‘farmer applied’ pain relief products. A topical anaesthetic (TA) gel (Tri-Solfen®, Bayer Animal Health Australia) designed to be absorbed through tissue in open wounds, and a buccal meloxicam (BM) gel (Ilium® Buccalgesic OTM, Troy Laboratories) designed for oral trans-mucosal absorption, have been developed for post-operative anaesthesia and analgesia of lambs and calves undergoing surgical husbandry procedures. This thesis has aimed to assess the efficacy of TA and BM, singly and in combination, for the relief of post-operative pain caused by surgical castration and amputation dehorning of calves. This thesis has also aimed to assess the efficacy of a vapocoolant spray as a practical option for providing temporary local anaesthesia for alleviation of intra-operative pain during surgical castration. Results of all studies suggest that TA and BM result in some amelioration of pain caused by castration and dehorning of calves, with indications of increased efficacy when a combination of TA and BM is used. The results suggest that TA and BM do not completely abolish pain following castration and dehorning of calves and therefore further improvements to analgesic therapies for these procedures should be investigated