A 1.5-year-old spayed female Great Pyrenees mix was presented for evaluation and surgical repair of a caudal palatal defect that was previously identified as a “cleft palate.” She had received two previous unsuccessful surgical repair attempts and had a history of chronic rhinitis and nasal discharge of food material. Upon examination, the defect in the caudal hard palate was more morphologically consistent with an acquired oronasal fistula. Her diagnostic workup included a head CT, full-mouth intraoral radiographs, bloodwork, thoracic radiographs, and rhinoscopic examination and biopsy for histopathology. Due to the fistula’s size, location, and surrounding tissue quality, a staged surgical approach was elected to first perform selective extractions, then close the defect following adequate soft tissue healing. A polyvinyl siloxane obturator temporarily blocked the fistula until it was definitively closed using a double-layer modified major palatine transposition flap technique. Postoperative success has thus far been confirmed at recheck examinations.