Regional Analgesia of the Horse's Head

Regional analgesia has been used routinely for musculoskeletal diagnostic nerve blocks and regional analgesia for standing surgical purposes. it is only more recently that a greater variety of surgical procedures are performed in the head and the true value of desensitising these tissues has become apparent. the indications for regional analgesia in the head are to provide analgesia and selective paralysis of structures to facilitate ancillary diagnostic or surgical procedures, and some blocks can be used as diagnostic nerve blocks.

Procedures which are performed routinely where local analgesia greatly facilitates the technique include: eyelid surgery, dental surgery and periodontal procedures, paranasal sinus surgery, mandibular fracture repairs, and transendoscopic laser surgery.

Diagnostic techniques to localise pain can be used where temporomandibular joint pathology is suspected or to attribute signioficance to dental lesions in dysphagic cases or to test the efficacy of treatment techniques for head shaking. it should be assumed that the application of any nerve blocks to the head will be resented by the horse and therefore it is strongly recommended that these techniques are practised in horses that are already well sedated.

My preference is to combine the regional analgesia with a multimodal approach involv- ing benzodiazapime/ alpha 2 adrenoceptor agonist sedation, parenteral analgesia with opiates and non-steroidal anti-inflammtory drugs and local analgesia. the techniques are easily practised in the field but the advantages of performing most head procedures in a clinic where the environment can be controlled and any complications can be man- aged far outweighs the disadvantages of having to transport the horse. Where possible, i recommend that horses are restrained in stocks for better safety of clinicians and lay spectators. [...]