A COMPARISON OF THE ANALGESIC EFFECTS OF INTRATHECAL LIDOCAINE, XYLAZINE AND THEIR COMBINATION IN DONKEYS

This study was performed on 15 nonmedicated clinically healthy donkeys of both sexes. The animals were classified into three equal groups according to the type of the anaesthetic used for inducing intrathecal analgesia. Animals of the first group were injected lidocaine HCL 2%. Animals of the second group were injected xylazine HCL 2% while a mixture of both drugs was injected in the third group. All animals received the same volume of anaethetic solution and the injection rate was 0.5 ml/minute. The onset, duration and anaesthetized area were determined in each group. It was found that lidocaine gave immediate onset and short duration (about one hour). Analgesic effect started 5 minutes after the end of xylazine injection and lasted more than four hours. When a mixture of both drugs used in the third group, the onset of analgesia was after three minutes and continued for about 3.5 hours. In all animals the anaesthetized area was the same. It was noticed also that the degree of analgesia induced by xylazine was nearly equivalent to that of lidocaine. The present study showed that intrathecal xylazine can be used for anaesthesia of a prolonged surgical interferences.