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Combined xylazine and ketamine as an analgesic regimen in sheep
Author(s) -
HUGHAN SC,
LOOSE JM,
CADDY DJ,
CANNY BJ,
TILBROOK AJ,
YOUNG IR
Publication year - 2001
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.2001.tb14582.x
Subject(s) - xylazine , medicine , ketamine , anesthesia , analgesic , general anaesthesia , prolactin , placebo , surgery , hormone , alternative medicine , pathology
Objective To determine whether low dose xylazine with ketamine reduces the concentrations of cortisol and prolactin in sheep postoperatively and to characterise the effects of the drugs on behaviour during recovery. Design Analysis of variance was used to compare the effects of anaesthesia, surgery and combined ketamine/ xylazine treatment on the plasma cortisol and prolactin concentrations and on behavioural variables in pregnant ewes subjected to abdominal surgery. Procedure Twelve ewes were randomly assigned to receive either ketamine/xylazine or placebo in association with anaesthesia and surgery. Both groups of ewes underwent anaesthesia alone followed a week later by anaesthesia with laparotomy and hysterotomy. Plasma cortisol and prolactin concentrations were assayed during these procedures and for 5 days afterwards. Behavioural observations were made remotely during recovery from anaesthesia and anaesthesia plus surgery. Results The concentrations of cortisol in the plasma of pregnant ewes undergoing surgery were increased by preoperative handling and the onset of thiopentone/halothane anaesthesia, with a further increase during surgery (P = 0.033). Cortisol concentrations decreased over the first four postoperative hours (P = 0.029) and were normal by 24 h. The drug treatment did not affect the immediate responses of ewes to anaesthesia or surgery, although treated ewes had lower cortisol concentrations than saline‐treated controls over the first five postoperative days (P = 0.018). Prolactin concentrations increased in response to anaesthesia (P = 0.047), but were not affected by surgery or the drug treatment. Drug‐treated ewes had prolonged sleeping time after surgery (P = 0.002), but they took no longer to stand than saline‐treated controls and required fewer attempts to stand successfully (P = 0.025). Conclusion At the doses used, ketamine and xylazine did not mitigate the immediate endocrine consequences of surgery but the behavioural data provide a basis for further investigations that may lead to improvements in analgesic treatments.