Pudendal Nerve Blockade Is Superior to Epidural Analgesia for Andrological and Surgical Procedures on the External Genitalia of Male Goats in the Standing Position

The aim of the present study was to evaluate the efficacy of pudendal nerve block as an alternative procedure to epidural analgesia for penile relaxation in male goats. Five healthy male goats were subjected to pudendal nerve block and lumbosacral epidural analgesia with a two-weeks interval as a washing period. Bilateral pudendal nerve block was performed using 1% of lidocaine hydrochloride (HCl) by ischiorectal fossa approach. Lumbosacral epidural analgesia was performed using 1% of lidocaine HCl in the lumbosacral space. Nociception was investigated by pinprick. Time to the onset and duration of the anti-nociception effect in the perineal region were recorded. Area of desensitization and penile relaxation were observed. Incoordination, ataxia, and analgesic effects were carefully observed and recorded according to the scoring system before analgesic administration and at 5-, 15-, 30-, 60-, and 90-min after administration. Pulse rate, respiratory rate, and rectal temperature were recorded at 0-, 5-, 15-, 30-, 60-, and 90-min after administration. This study showed that both the pudendal nerve block and the epidural analgesia resulted in analgesic effects, however, the penile relaxation without manipulation was observed in 4 out of 5 male goats subjected to the pudendal nerve block. None of the male goats subjected to lumbosacral epidural analgesia showed penile relaxation, spontaneously. The time of onset was significantly earlier in the pudendal nerve block compared to the epidural analgesia, Moreover, the duration of action was significantly shorter in the pudendal nerve block compared to the epidural analgesia. Incoordination, ataxia, and recumbency were observed in 3 out of 5 male goats subjected to epidural analgesia. In conclusion, the pudendal nerve block is likely superior to the epidural analgesia for examination of the penis and surgical procedures on the male goat reproductive system in the standing position.