A new antimicrobial ear cleanser was evaluated for the treatment of bacterial and yeast ear infection in dogs. Forty-five dogs with erythemato-ceruminous or purulent otitis externa were randomly allocated to two treatment groups: reference ear cleanser (Epiotic, Virbac) or test ear cleanser (Epiotic Advanced, Virbac). Ear cleansing was performed twice daily for 2 weeks, and no other treatment was allowed. By week 2, clinical (exudate quantity, erythema, stenosis, excoriation, and odor) and discomfort (pain, ear scratching, and head shaking) scores were significantly decreased (P < .0001 for all) and no microbial overgrowth could be detected in 25 (64.1%) and 32 (68.1%) ears treated with Epiotic and Epiotic Advanced, respectively. The new pH-balanced, propylene glycol-free test ear cleanser, which incorporates microbial adhesin-blocking carbohydrates, proved as effective as the reference acidic formula.