The efficacy of an ointment containing kunzea oil for the treatment of horses with localised acute or chronic pastern dermatitis was assessed. Thirty-seven horses were randomly allocated to treatment with an ointment containing either 20 per cent kunzea oil (test) or 2 per cent ketoconazole (control). Only 21 of the horses completed the study. The severity of the lesions was assessed before and after seven days of treatment. The kunzea oil formulation resulted in a significant decrease in the median total area of the lesions from 40 cm(2) (range 3 to 252 cm(2)) to 0 cm(2) (range 0 to 34 cm(2)), with complete resolution of the signs of pastern dermatitis in seven of 11 cases. The control formulation resulted in no significant change in the total area of the lesions, and the signs of pastern dermatitis resolved completely in only two of the 10 cases.