A Rare Case of Occipitoatlantoaxial Malformation Accompanied by C۲–C۳ Luxation in an ibex (Capra aegagrus): Clinical and Radiographic Findings

Background: Occipitoatlantoaxial malformation (OAAM) is a congenital craniovertebral junction defect reported in domestic mammals, rarely documented in wild species. Case Description: This case describes the radiographic and clinical manifestations of OAAM concurrent with C۲-C۳ joint luxation in a ۱.۵-year-old female ibex (Capra aegagrus) from the Sefidkooh Protected Area, Lorestan, Iran. The animal exhibited severe neurological symptoms, including paddling, nystagmus, and lateral recumbency, as well as respiratory distress (dyspnea), following its fall from a cliff. Lateral radiographs revealed fusion of the occipital bone with an amorphous bony mass replacing the atlas (C۱), extending over the anterior portion of the axis (C۲), along with hypoplasia of the caudal articular process of C۲ and luxation at the C۲-C۳ intervertebral joint. No significant findings were observed during necropsy or laboratory testing. Results and Conclusion: Based on exclusion of traumatic fracture, discospondylitis, and metabolic neuropathies, and in accordance with radiographic criteria described in equine and canine OAAM cases, a diagnosis of congenital OAAM was established. This report represents the first documented case of OAAM in an ibex, suggesting its broader occurrence across Caprinae and highlighting the importance of radiological surveillance in wildlife trauma diagnostics.

کلیدواژه ها:

Ibex ، OAAM ، Occipitoatlantoaxial malformation ، Radiography ، Cervical luxation ، Capra aegagrus