Investigation of a progressive facial deformity and stridor in an adult horse with a bone sequestrum and subsequent sinonasal abscess.

Advanced diagnostic imaging and histopathological investigation were performed in an adult horse with chronic facial swelling due to a bone sequestrum and abscessation. In contrast to other cases, there were no draining tracts, difficulty eating, weight loss, head shaking, or fistula formation between the oral cavity and the maxillary sinus.