Caudal Epidural Anesthesia in Adult Dairy Cows with Procaine 2%: Comparison of 3 Volumes for Perineal Anesthesia

16 adult cows (480-780 kg) received randomly 5, 10 or 15 ml of procaine 2% (G5, G10, G15) by caudal epidural injection to assess anaesthetic blockade of the perineal area by a pressure algometer. 2 Cows were excluded resulting in 4 cows in G5, 6 cows in G10 and 4 in G15. Statistical analysis included a Wilcoxon Mann Withney test and a fisher exact test with a p value set at 0.05. Anaesthesia failed to develop in 1 cow/4 in G5 and was deemed insufficient for the other 3 cows with a longer onset and a shorter duration than for G10 and G15 (p<0.05). G10 and G15 had a similar onset (within 10 minutes), duration (40-110 min) and spread of blockade to the perineal area, the tail and the caudal aspect of the thighs. Ataxia developed in one cow/6 in G10 and 3 cows /4 in G15. The volume of 10 ml of procaine 2% administered by caudal epidural injection in adult cows was deemed to be the best compromise between efficacy and side-effect. This result needs to be confirmed by a clinical study on cows submitted to obstetrical manoeuvres or perineal surgery.