A 6-year-5-month-old female neutered American Bulldog was referred to the dentistry and oromaxillofacial surgery department at Eastcott Referrals for assessment and treatment of a canine acanthomatous ameloblastoma of the right rostral mandible. Surgical planning involved the histopathology results, preoperative radiographs of the lesion, a high resolution computed tomography (CT), with and without contrast, and a 3D-printed model. The mass was excised by a left rostral mandibulectomy and immediately reconstructed with a titanium locking plate and compression resistant matrix infused with rhBMP-2. Tumour-free surgical margins were obtained and at 2 weeks post-surgery there was a large soft swelling palpable. Follow-up imaging (CT) at 8 weeks post-surgery revealed evidence of bridging new bone in the mandibular defect with a heterogeneous appearance, a fluid filled cystic lesion in the ventral intermandibular tissue and ectopic bone proliferation. Clinically the dog returned to normal lifestyle. At 16 months post-operatively the patient presented with sanguinous discharge for a repeat CT and it showed a draining sinus tract and amorphous ectopic mineralisation. These findings lead to the surgical decision to remove the implants. This presentation outlines a post-operative complication associated with the use of an osteoinductive factor (rhBMP-2/CRM) that had not previously been reported in dogs to this extent.