Modified technique for resection of the alar folds to nasal paralysis in a mule: Case report

Abstract Equids are obligate nasal breathers. Therefore, conditions that obstruct or impair this respiratory route can compromise animal welfare by causing severe respiratory distress, while also impacting athletic potential. Nasal paralysis results from injury to the facial nerve and its branches and is characterized by the lack of movement of the alar cartilage, leading to nasal collapse. Its occurrence is uncommon in horses and has not been previously reported in mules. This report describes a 9-month-old mule presented with a history of facial trauma and compression caused by a halter. After unsuccessful anti-inflammatory therapy and temporary retention sutures, resection of the alar cartilage was elected. The procedure was performed under general anesthesia with the patient positioned in sternal recumbency. Traction was applied to the apex of the alar cartilage lamina, followed by an elliptical skin incision. Upon exposure, the alar cartilage was resected, and the skin was closed using a simple continuous suture pattern. The patient showed satisfactory recovery, with maintenance of airway patency. Two months postoperatively, the animal remained stable with no signs of nasal collapse. The investigation of therapeutic options and the description of surgical alternatives for correcting nasal collapse are fundamental, as nasal paralysis, although uncommon, can lead to severe dyspnea, result in nasal collapse, and compromise both animal welfare and athletic performance.