Effect of local anaesthesia and/or analgesia on pain responses induced by piglet castration

Abstract

BackgroundSurgical castration in male piglets is painful and methods that reduce this pain are requested. This study evaluated the effect of local anaesthesia and analgesia on vocal, physiological and behavioural responses during and after castration. A second purpose was to evaluate if herdsmen can effectively administer anaesthesia.MethodsFour male piglets in each of 141 litters in five herds were randomly assigned to one of four treatments: castration without local anaesthesia or analgesia (C, controls), analgesia (M, meloxicam), local anaesthesia (L, lidocaine), or both local anaesthesia and analgesia (LM). Lidocaine (L, LM) was injected at least three minutes before castration and meloxicam (M, LM) was injected after castration. During castration, vocalisation was measured and resistance movements judged. Behaviour observations were carried out on the castration day and the following day. The day after castration, castration wounds were ranked, ear and skin temperature was measured, and blood samples were collected for analysis of acute phase protein Serum Amyloid A concentration (SAA). Piglets were weighed on the castration day and at three weeks of age. Sickness treatments and mortality were recorded until three weeks of age.ResultsPiglets castrated with lidocaine produced calls with lower intensity (p < 0.001) and less resistance movements (p < 0.001) during castration. Piglets that were given meloxicam displayed less pain-related behaviour (huddled up, spasms, rump-scratching, stiffness and prostrated) on both the castration day (p = 0.06, n.s.) and the following day (p = 0.02). Controls had less swollen wounds compared to piglets assigned to treatments M, L and LM (p < 0.001). The proportion of piglets with high SAA concentration (over threshold values 200, 400 mg/l) was higher (p = 0.005; p = 0.05) for C + L compared to M + LM. Ear temperature was higher (p < 0.01) for controls compared to L and LM. There were no significant treatment effects for skin temperature, weight gain, sickness treatments or mortality.ConclusionsThe study concludes that lidocaine reduced pain during castration and that meloxicam reduced pain after castration. The study also concludes that the herdsmen were able to administer local anaesthesia effectively.

Pain behaviour after castration of piglets; effect of pain relief with lidocaine and/or meloxicam

“…Castrated piglets treated with meloxicam showed the same level of No pain-related behaviour as piglets that were not castrated (SHAM and NONE), and showed significantly more No pain-related behaviour than castrated piglets (with or without lidocaine). This positive effect of meloxicam on behaviour, during 1 day after castration, confirms the findings of Keita et al (2010) and Hansson et al (2011). They studied behaviour during a few hours to 1 day after castration.…”

“…However, a thickening of the scrotum was found in several LIDO, MELO and L 1 M piglets, as opposed to CAST piglets. This is also reported by Hansson et al (2011). An explanation for this thickening remains unclear.…”

“…It is the only NSAID in The Netherlands that is registered for post-operative pain relief in piglets following minor surgery. Keita et al (2010) and Hansson et al (2011) have shown a beneficial effect of meloxicam on behaviour during the 1st day after castration. A prolonged effect of meloxicam on piglet behaviour on successive days has, to our knowledge, not yet been investigated.…”

Carprofen neither reduces postoperative facial expression scores in rabbits treated with buprenorphine nor alters long term bone formation after maxillary sinus grafting

“…In a study of piglets undergoing castration, SAA levels were lower in piglets that received meloxicam in comparison to controls (Hansson et al, 2011). The levels in the current study were similar to those in a study on NZW rabbits undergoing knee cartilage surgery (Aulin et al, 2013).…”

Can novel methods be useful for pain assessment of castrated piglets?

“…During the last years, methods to reduce pain with anaesthesia and/or analgesia were investigated (Sutherland et al, 2010;Hansson et al, 2011;Kluivers-Poodt et al, 2012). In order to monitor suffering after mutilation, several pain indicators are commonly considered such as physiological (including a clinical and a neuroendocrine approach) and behavioural parameters (Weary et al, 2006;Sutherland et al, 2012).…”