Visual evidence of progression and eventual resolution of nasofrontal suture exostosis over 27 months in a gelding

A 22-year-old Thoroughbred gelding presented with a noticeable external firm and nonpainful swelling over the location of the frontal sinuses. Further radiographic investigation of the swelling identified soft tissue facial swelling, new bone formation and a radiolucent line between two areas of bone remodelling. The horse was diagnosed with a nasofrontal suture exostosis. This is a relatively rare disease of the head but is one of the more common reasons for facial swelling. It is reported that these horses are not painful and that the swelling and bony reaction will resolve over 12–18 months with no treatment needed. It is well described in the current literature what the initial presentation should look like; however, there is a void when it comes to demonstration of the clinical course of the disease. This report provides veterinarians and owners with a visual reference to a relatively typical course of disease, where swelling can enlarge over time and still resolve within 2 years.