Pierdon, M. K., Berdahl, S. E. 2023. Effect of topical spray containing lidocaine on piglet behaviour post castration. Journal of Applied Animal Welfare Science 26(2), 195–204.

Previous studies examining the impact of topical lidocaine spray on postcastration pain behavior in piglets used scan sampling for the collection of behavior data. This methodology led to inconclusive results on the efficacy of topical lidocaine spray for pain relief. This study uses continuous coding to examine the effect of topical lidocaine on piglet behavior post castration. Castrated piglets received either no pain relief or topical lidocaine spray and are compared to gilts that were handled only. Postcastration piglet behavior was continuously coded for postural behaviors, social isolation, as well as nosing and playing. Behaviors in the castrated piglets differed from those that were handled only, but the piglets that received the spray did not exhibit significantly different behaviors from castrated pigs that received no spray. Play, exploratory behavior, and continuous behavioral observations proved to be sensitive modalities for detecting alterations in behavior postcastration and revealed that topical lidocaine spray does not provide effective pain mitigation for piglets undergoing castration and would thus not be recommended as a method for providing postcastration pain relief in piglets.