Mean respiratory rates of goats undergoing laparotomy administered either lidocaine alone or a mixture of lidocaine and tramadol combination over time. *Denotes significant difference (p <0.05) between baseline data at 0 hour and corresponding respiratory rates at 1 hour and 5 hour in lidocaine alone group, whilst a,b and c indicates significant difference (p < 0.05) within lidocaine-tramadol group at 4 hour, 5 hour and 6 hour after administration of the lidocaine-tramadol mixture.