Diamond Frog Dressing (formally called Diamond Thrush Treatment) reduces the number of bacteria and fungi and builds a protective layer to maintain optimum hoof health. When the color has faded, you know it is time to repeat.The gel formula does not run when applied. It bonds to the hoof protein to form a barrier between thrush and healthy tissue. The blue color shows where product has been applied with a flexible tip applicator for better placement of treatment.