A definitive diagnosis of extensive suture line exostoses affecting the nasofrontal, nasolacrimal,
nasomaxillary, frontolacrimal, lacrimozygomatic and lacrimomaxillary suture lines in a 7-year-old
Thoroughbred mare with chronic bilateral epiphora and facial deformation was achieved using
standing computed tomography (CT) examinations. Positive contrast dacryocystorhinography
using CT revealed partial bilateral obstruction of the nasolacrimal ducts. Minimally displaced
depression fractures of the right nasal bone, the right maxillary bone and right frontal bone were
also demonstrated. The cosmetic appearance of the periosteal reaction associated with the suture
line exostosis and epiphora significantly improved within 3 months of diagnosis and treatment.