Surgical repair of a chronic,oronasal fistula in a horse using an alveolar bone flap

An 8‐year‐old Andalusian stallion was presented to the Equine Hospital with a 1.5 year history of an oronasal fistula measuring approximately 2 cm long (caudal to rostral) by 1.5 cm wide following an oral extraction of the right second maxillary premolar (106). An alveolar bone flap was created adjacent to the oronasal fistula and rotated axially and ventrally to close the oral aspect of the fistula. At 3 days after surgery, clinical signs of the fistula, such as green‐tinged purulent nasal discharge and malodorous breath, were no longer evident. At 10 days after surgery, the oral opening of the fistula filled with granulation tissue and mucosa and decreased in size to less than 2 ml. The horse was fed a pelleted mash and grass diet and the small fistula was flushed orally twice daily until it completely healed. At 6 months following surgery, the fistula had completely healed. Few options are available for repairing an oroantral or an oronasal fistula in horses. This case report suggests that a large, chronic oronasal fistula involving the alveolus of a maxillary second premolar can be repaired successfully with an alveolar bone flap.