Article Text

Maintenance of anaesthesia in sheep with isoflurane, desflurane or sevoflurane
  1. A. R. Mohamadnia, DVM, DVSc1,
  2. G. Hughes, HND(Ag), HNC(Sci)2 and
  3. K. W. Clarke, MA, VetMB, DVetMed, DipECVA, DVA, FRCVS2
  1. 1 Department of Clinical Sciences, College of Veterinary Medicine, 2 Saman Road, University of Shahrekord, Shahrekord, 88186/34141, Iran
  2. 2 Royal Veterinary College, Hawkshead Lane, Hatfield, Hertfordshire AL9 7TA


Rapid recovery from anaesthesia is advantageous in small ruminants, to reduce the risk of regurgitation. Theoretically, the least soluble inhalation agents should result in the fastest recoveries, but using additional injectable agents may negate this advantage. This study compared three inhalation agents for the maintenance of anaesthesia in sheep. Eighteen ewes that were to undergo orthopaedic surgery were allocated to one of three groups. Each group was premedicated with xylazine (0·1 mg/kg intramuscularly), anaesthesia was induced using ketamine (2 mg/kg) and midazolam (0·03 mg/kg) intravenously and analgesia provided by buprenorphine (0·008 mg/kg intramuscularly). Anaesthesia was then maintained with either isoflurane, sevoflurane or desflurane. Cardiopulmonary parameters were monitored throughout. All three inhalation agents provided adequate stable anaesthesia and there was no significant difference between the groups in their cardiopulmonary parameters or their recovery times. The mead (sd) postanaesthetic times to first swallow, first chewing attempts and ability to maintain their head lifted for five minutes were, respectively, 3·95 (2·53), 6·37 (3·68) and 32·8 (18·1) minutes for isoflurane, 3·62 (0·98), 7·66 (0·78) and 38·8 (16·6) minutes for sevoflurane, and 4·37 (1·65), 6·95 (1·52) and 29·8 (11·5) minutes for desflurane. Two sheep had poor quality recoveries after the use of sevoflurane, but all the other sheep recovered uneventfully. All three inhalation agents were suitable for the maintenance of anaesthesia in sheep but, as used in this study, there were no differences between them in speed of recovery.

Statistics from

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.