Effects of a Multimodal Pain Control Protocol Using 2% Lidocaine Intradermal and Meloxicam Intramuscular on Mitigating Behavioral Castration Pain in Piglets Using a Needleless System.

Mitigating piglet castration pain is critical to minimize negative experiences and contribute to a positive affective state. A multimodal pain control protocol (needleless 2% lidocaine intradermal/0.4 mg/kg meloxicam intramuscular) was evaluated. Males were administered one of four treatments: (1) needleless lidocaine/meloxicam intramuscular (LM), (2) needleless lidocaine/saline intramuscular (LS), (3) needleless saline/meloxicam intramuscular (SM), and (4) needleless saline/saline intramuscular (SS). Females were sham castrated (SH). Piglets were recorded 24h pre-castration (M1) and 15min (M2), 3h (M3), and 24h post-castration (M4). The Unesp-Botucatu Composite Acute Pain Scale (UPAPS) was used to assess pain behavior. From a treatment standpoint, scores did not differ at M1 (P = 1.00) or M4 (P ≥ 0.36). However, at M2, LS piglets had (P < 0.01) higher scores (3.4) than LM piglets (1.6) and SH piglets had (P ≤ 0.01) the lowest scores (0.02). From a timepoint standpoint, piglets in the LS, LM, SM, and SS groups had (P ≤ 0.05) higher scores at M2 compared with their baseline scores at M1. These results indicate that needleless lidocaine and intramuscular meloxicam offered no analgesic benefit.