Anaesthesia and analgesia for sheep

This chapter describes the approach to general and local anaesthesia and analgesia for sheep. The main challenges of general anaesthesia include the management of regurgitation, salivation, bloat, hypoxaemia and hypercapnia. Strategies to mitigate these risks are presented. The advantages and disadvantages of drugs commonly used for sedation, anxiolysis, premedication before general anaesthesia and pre-emptive analgesia are described. Anaesthesia is usually induced by the intravenous route and maintained by gaseous agents or the repeated administration of intravenous or intramuscular drugs. Techniques for induction, maintenance and monitoring during anaesthesia and recovery are discussed. Local anaesthesia can be provided by drug administration locally or through regional blocks using paravertebral, lumbosacral or sacrococcygeal approaches. The main classes of analgesic drugs are the non-steroidal anti-inflammatory drugs, opioids, local anaesthetics, alpha-2 adrenoreceptor agonists and NMDA receptor antagonists. A non-steroidal anti-inflammatory and a local anaesthetic should be the minimum approach for any case where pain may be caused.