Efficacy of Procaine, With and Without Epinephrine, Compared to Lidocaine in Local Anesthesia for Calves Before Thermocautery Disbudding

Within the European Union, the use of lidocaine in food-producing animals is restricted due to concerns over human safety. This study compared the clinical effectiveness of procaine, with and without epinephrine, against lidocaine in pain alleviation during thermocautery disbudding in xylazine-sedated calves. The efficacy of local blocks was assessed through needle pricks, and the behavioral reactions to disbudding were scored. Post-disbudding pain was subjectively evaluated, and pressure pain threshold and tactile sensitivity around the horn bud were assessed at intervals. Blood was collected at intervals for plasma cortisol analysis. No significant differences were found between the groups in the needle prick test (p = 0.329) and the disbudding score (p = 0.855). Pain scores and quantitative sensory tests showed no significant differences between the lidocaine and procaine-epinephrine groups. Conversely, tactile sensitivity and pain scores were significantly higher, and pressure pain thresholds were significantly lower with procaine alone than in other groups. Elevated cortisol concentrations were observed in all groups before disbudding compared to the baselines. The results suggest that procaine combined with epinephrine appears to be a safe and effective alternative to lidocaine for calf disbudding. Cortisol concentrations as an indicator of pain in xylazine-sedated calves appear inadequate.