594450 Disclosed is a pharmaceutically and physiologically acceptable anti-microbial composition including a therapeutically effective amount of the active agents: (a) at least one sulphonic acid; and (b) lactic acid; and (c) at least one citrate compound; wherein the composition is a water soluble liquid formulated for topical application to a nonhuman animal. Also disclosed are methods of treating a microbial infection or sterilising the skin in a non-human animal by applying the composition. Furthermore is the sterilising of the skin area from the bacteria Corynebacterium bovis.