Endodontic therapy in nondomestic species presents unique diagnostic and therapeutic challenges, particularly when prior unsuccessful treatment has compromised tooth and periapical health. This case report describes the management of a mandibular canine tooth in a spotted hyena (Crocuta crocuta) that had previously undergone unsuccessful endodontic therapy performed outside the reporting institution. Clinical examination and diagnostic imaging revealed an open apex with associated periapical lucency, consistent with persistent endodontic pathology. Apexification was elected as the treatment approach, utilizing mineral trioxide aggregate (MTA) to achieve an apical barrier and promote periapical healing.

The procedure was completed without complication, and follow-up evaluations demonstrated satisfactory clinical and radiographic outcomes, including resolution of the periapical lucency. This case highlights the applicability of MTA apexification techniques in nondomestic carnivores and underscores the value of appropriate endodontic retreatment strategies in preserving strategically important teeth.