Successful Management of Vagosympathetic and Recurrent Laryngeal Nerve Damage with Retropharyngeal Space Deformity after Atlantoaxial Implant Explantation in a Dog

A 7-month-old neutered male Poodle underwent ventral stabilization for atlantoaxial instability caused by neck pain.One year later, the patient developed severe cough and vomiting.Radiography revealed implant failure affecting the upper esophagus and airway, necessitating explantation.After the explantation, the patient presented with acute dyspnea, dysphagia, and dysphonia.Neurological examination revealed right eye miosis, and the ear pinna on the same side was hyperemic.Computed tomography imaging showed retropharyngeal space deformity, and gross examination of the larynx revealed unilateral laryngeal paralysis.Supportive management was initiated using tracheostomy and gastrostomy tubes.The clinical signs showed improvement by postoperative day (POD) 6, and full recovery was observed by POD 37.In this study, a canine case of vagosympathetic trunk and recurrent laryngeal nerve paralysis with retropharyngeal deformity after atlantoaxial implant explantation is reported, and the clinical course and management of these complications is also presented.