Influence of local anaesthesia on pain and distress induced by bloodless castration methods in young lambs.

摘要

Behavioural and cortisol responses of lambs were used as indicators of pain and distress to assess the short- and long-term effects of bloodless castration methods with and without local anaesthesia. 80 lambs, aged 2-7 days, were control handled or castrated by crushing, Burdizzo or rubber ring methods with and without local anaesthesia. Either 4 mg/kg diluted lidocaine or corresponding volumes of physiological sodium chloride solution was distributed in both the spermatic cord and scrotal neck. The serum cortisol response was monitored for 48 h, whereas behavioural and clinical traits were observed for 3 months. The crushing castration method was excluded from the study after 10 lambs had been castrated, since this method showed severe local reactions. Local anaesthesia significantly reduced the behavioural and cortisol responses after rubber ring castration and tendentially after Burdizzo castration. Prolonged or chronic pain after rubber ring castration with anaesthesia was not evident. If combined with local anaesthesia, both the rubber ring and Burdizzo methods were acceptable for castration of lambs up to one week of age..