Amlodipine-induced gingival hyperplasia in a Great Dane

A 3 yr old, 70 kg (154 lbs) female spayed Great Dane developed gingival hyperplasia after treatment of systemic hypertension with amlodipine 7.5 mg q 12 hr for 16 mo. Physical examination was unremarkable except for systemic hypertension and severe gingival hyperplasia. Amlodipine was replaced with hydralazine (0.72 mg/kg [0.32 mg/lb]). Nine months later, gingival hyperplasia was nearly resolved and hypertension was well controlled. Calcium channel blockers such as amlodipine are a rare cause of gingival hyperplasia in the canine patient. Recognition of this side effect is important because a full recovery can be achieved when the offending agent is removed.