Medication-related osteonecrosis of the jaw after long-term bisphosphonate treatment in a cat.

A 12-year-old, neutered female, domestic medium hair cat was evaluated for a nonhealing, oral mucosal ulceration. The cat had a history of idiopathic hypercalcemia that had been treated with a bisphosphonate for 41 months. Oral examination identified exposed maxillary bone adjacent to a previous extraction site. Histopathology of the exposed bone and associated mucosa was most consistent with medication-related osteonecrosis of the jaw. Treatment involved both medical and surgical interventions. Oral mucosal healing occurred after 6 months of treatment.