Abstract:
Bilateral paranasal sinus diseases are rarely reported in horses. Treatment using a bilateral
frontonasal bone flap on a standing, regular-sized adult horse has not been described
previously. A 13-year-old Thoroughbred gelding was evaluated for bilateral mucopurulent
nasal discharge. Radiographic, endoscopic and computed tomographic examinations revealed
bilateral sinus pathological changes consistent with an ethmoid haematoma involving the
maxillary and frontal sinuses. A bilateral frontonasal bone flap was created under standing
sedation and local anaesthesia. A tracheotomy was performed initially to ensure a patent
airway during the procedure. Additional analgesia had to be given to transect the dorsal part
of the nasal septum while elevating the flap. The sinus masses were removed and
communications with the nasal cavities created uneventfully. Small sequestra were removed
transendoscopically from the left caudal maxillary sinus 4 weeks after the initial procedure.
The horse made a complete recovery with an excellent cosmetic outcome. Histopathology
revealed the mass to be a sinus cyst. We concluded that a bilateral sinus bone flap can be used
in adult regular-sized horses to access the left and right paranasal sinuses simultaneously.
Regional nerve blocks should be performed in order to increase analgesia. A temporary
tracheotomy prevents any airway obstruction during the procedure. The post-operative
cosmesis is excellent.
