@article{4580, keywords = {pain mitigation, anaesthesia, Biomarker}, author = {M Sheil and A Polkinghorne}, title = {Optimal pain indicators for field trial assessment of analgesic efficacy in piglets undergoing surgical castration}, abstract = {There is a growing demand for pain mitigation strategies that improve the welfare of piglets undergoing surgical castration in commercial pig production systems. While a range of potential anaesthetic and/or analgesic interventions have been trialled, efforts to confirm efficacy in field use, are stymied by the absence of ‘gold-standard’ methods to measure pain experienced by piglets during and after surgical castration. A review of the available literature in this field reveals that many methods commonly utilised to measure piglet pain lack sensitivity and/or specificity and may be unreliable. Measurement of biomarkers of physiological responses to pain, for example, appear to be readily confounded by similar responses to handling and restraint and/or to tissue trauma, which may occur in the absence of piglet pain. Similarly, it is challenging to accurately document pain-related behaviours in neonatal piglets following castration, since such behavioural disturbances are subtle, variably expressed and short-lived as compared with those undergoing handling only. Of the methods reviewed, nociceptive motor responses and/or vocal responses during the procedure, and targeted direct observation of specific pain-related behaviours, along with mechanical sensory testing for sensory hyperalgesia following the procedure, appear to be the most reliable methods for detection of pain in neonatal piglets, with significant differences most consistently observed between castrated and non-castrated animals, and/or those receiving analgesia/anaesthesia versus those left untreated. Understanding the strengths and weaknesses of current methods of measuring perioperative pain in piglets is critical to ongoing efforts by stakeholders to develop effective pain mitigation strategies. }, year = {2021}, journal = {Berliner und Münchener Tierärztliche Wochenschrift}, volume = {134}, pages = {1-10}, month = {03/2021}, publisher = {Schlütersche Fachmedien GmbH}, address = {Hannover}, issn = {1439-0299}, doi = {10.2376/1439-0299-2020-38}, language = {English}, }