Description and evaluation of ultrasound-guided infraorbital nerve block in dromedary camel (Camelus dromedarius): a cadaveric study

In dromedary camels, general anesthesia is often avoided because of the risk of cardiopulmonary complications, high cost, and clinical challenges in field settings. Sedation combined with locoregional anesthesia may present a safer alternative for facial and dental interventions. While ultrasound-guided techniques are well established in other species, their application in camels remains unexplored. This study aimed to describe and evaluate the feasibility and anatomical accuracy of the ultrasound-guided infraorbital nerve block technique in camel cadavers. Eight adult dromedary camel cadaver heads, obtained from four males and four females, were examined. The camels had a median age of 45 months (range, 42–50 months) and a median body weight of 400 kg (range, 385–410 kg), yielding a total of 16 nerve staining procedures (superficial and deep, and bilateral) via an extraoral approach. Using a 5 MHz curved array ultrasound probe, the infraorbital canal was visualized under real-time guidance. For the superficial block, a 20G 32 mm blunt-tipped cannula was inserted into the infraorbital canal and 1 ml of a methylene blue-saline solution (50:50) was injected. For the deep block, a 22G 90 mm spinal needle was advanced through the cannula to the pterygopalatine fossa, and 5 ml of the same dye solution was injected. Postprocedural dissection was used to assess dye spread and anatomical accuracy. The procedure was feasible, with a median procedural time of 2 min (range 1.5–3 min) for complete unilateral procedure comprising both superficial and deep injections. Ultrasound provided clear visualization of the infraorbital canal and associated neurovascular structures. The superficial blocks produced a median nerve staining length of 3.0 cm (range 2.5–3.5 cm), while the deep blocks stained a median of 10.1 cm (range 9.5–11.0 cm) of the infraorbital nerve, with dye reaching the pterygopalatine fossa in all specimens. No macroscopic nerve or tissue damage was observed. The primary limitation is the cadaveric nature of the study, which does not account for physiological variables, tissue turgor, or pain response. Clinical validation in live, sedated camels is needed. This study introduces an ultrasound-guided technique for infraorbital nerve block in camels, demonstrating anatomical feasibility and efficient dye staining in cadaveric specimens. The technique needs further validation in live animals before field application.