The Avian-RUM Block: A Locoregional Technique for Distal Wing Procedures in Birds-An Anatomical Cadaveric Feasibility...

Anaesthesia in avian species presents significant challenges due to high peri-anaesthetic mortality rates and marked anatomical variability. Multimodal anaesthetic protocols incorporating locoregional techniques are advocated to improve analgesia and minimise systemic drug requirements. While brachial plexus blocks are described for avian wing surgery, the proximity to major vessels and air sacs increases the risk of complications. This study introduces the "Avian-RUM block," a novel locoregional technique for the distal wing, adapted from the mammalian RUMM block but modified to reflect avian neuroanatomy, which lacks a distinct musculocutaneous nerve. Twelve rock doves (Columba livia) and twelve hooded crows (Corvus cornix) received transcutaneous injections of a dye solution targeting the radial and median-ulnar nerves at two volumes (0.15 and 0.3 mL/kg). Both species demonstrated high rates of nerve staining and procedural feasibility, with no significant difference in staining length between volumes. An illustrative clinical application of the Avian-RUM block in a domestic goose is also reported to contextualise the cadaveric findings within a multimodal perioperative setting. The results confirm the feasibility of the Avian-RUM block and its potential as a simple, equipment-free technique for regional anaesthesia of the avian wing. These findings provide a foundation for future clinical validation across bird species.