[The efficacy of local anaesthetics administered prior to castration of male suckling piglets].

Objective of this study was to examine the efficacy of various local anaesthetics (Procaine Hydrochloride, Procaine Hydrochloride + Epinephrin, Lidocaine Hydrochloride) used in castration of four to six day old male piglets. Animals of the control groups (I-IV) were treated analogous to the castration groups (V-IX) but not castrated. In groups I and V 15 minutes prior to castration/fixation the piglets were fixed as for injection but not medicated. The injection volume was standardised to 0.5 ml per testes. Local anaesthetics were applicated intratesticularly in five groups and intrascrotarly in two groups. Blood samples were taken shortly before and one, four and 24 hours after castration/fixation. The serum cortisol level was analysed to determine pain induced neuroendocrine stress reaction. To proof the tissue tolerance creatinkinase-(CK) and aspartataminotransferase-(AST) concentration were analysed. One, seven and 14 days after castration the healing process were evaluated by a wound score. Groups I to IV did not show any increase of the serum cortisol level. Contrary one hour after castration the average cortisol concentration of castration groups (V-IX) rose significantly. Cortisol concentration of the medicated castration groups (VI-IX) showed a comparable or even higher cortisol level as the not medicated control group (V). Determination of CK and AST indicated no tissue damage of the application of the local anaesthetics. The administration of local anaesthetics prior to the castration did not have any effect on the wound healing process. The results of this study lead to the conclusion that injection of local anaesthetics show a good tissue tolerance but the call for reduction of the castration pain by presurgical injection of Procaine Hydrochloride or Lidocaine Hydrochloride is not justified.