Effect of the number of incisions and use of local anesthesia on the physiological indicators of surgically-castrated piglets

Abstract

The objective of this study was to determine the effect of local anesthesia and the number of incisions performed on the physiological blood profile of piglets after surgical castration. A total of 60 male piglets were divided into five groups of 12 each, based on the surgical method employed and the use, or not, of local anesthesia, as follows: surgical castration using one horizontal incision in both testicles with (C1+L) and without (C1) local anesthesia; surgical castration using two vertical scrotal incisions with and without local anesthesia (C2+L and C2); and control piglets which were removed from their pens and held head-down by their hind limbs for approximately 90 s to simulate castration (SIM). Reference blood samples were drawn 24 h before castration (RV), immediately after surgery or simulated castration (PC), and at 24 and 48 h post-castration, to determine physiological profiles including; pH, hematocrit, glucose, electrolytes, lactate, pCO2 (mmHg), SO2 (mmHg), and bicarbonate. Results showed increases in lactate and hematocrit immediately after surgical or simulated castration with decreases in pH, HCO3− and base excess (BE). Surgical castration produced marked alterations of the physiological profile, detected by reduced pH and HCO3, higher lactate levels and BE alterations. These changes indicated metabolic acidosis that was greater in the piglets castrated surgically with one horizontal incision than in those castrated with two vertical incisions. More research is needed on the use of lidocaine during surgical castration, as it showed no effect on physiological profile in this study, but did alter hematocrit values. Keywords: Animal welfare, Blood gas test, Lidocaine, Local anesthesia, Orchiectomy, Physiological profiles