Assessment of intraoperative and postoperative pain after ruminotomy using xylazine as a sedative: differences between sheep and goats.

Abstract

The following study analysed the effects of xylazine administration on intraoperative and postoperative pain (both at 2 and 4 hours) comparing five Canary Island sheep and seven Majorera goats subjected to ruminotomy for the extraction of foreign bodies. For this purpose, parameters such as temperature were evaluated, which decreased in both species after the administration of the drug, obtaining significant differences between groups (sheep and goats) (p= 0.018). The respiratory frequency (RF) was also evaluated, which decreased, showing significant differences between groups (p=0.04). Another important parameter collected was heart rate (HR) which did not show significant variation differentiating both species. Finally, as far as physiological variables are concerned, oxygen saturation and mean arterial pressure (MAP) data were collected and it was found that there were no significant differences between the two species. In addition to the physiological parameters mentioned above, other parameters for pain assessment were collected and used in the Melbourne scale, which was adapted to these small ruminants and included: increased heart rate, mental state of each animal, vocalisation, pupil dilation, salivation, response to palpation of the wound, motor activity of both species and posture after the operation in order to analyse the expression of pain. Finally, to interpret pain, the sum of the scores of the previous behaviours was added up and it was observed that, although there were no significant differences in terms of the total value between species, some parameters that make up this total value independently, such as vocalisation (p=0.003), pupil dilation (p=0.013), mental state (p=0.006) and posture (p=0.000037) did show significant differences between the two species.