ZYMOX Shampoo is the recommended shampoo to use with ZYMOX Leave-On Conditioner because its known gentle plant surfactants will not affect the enzyme formula in the rinse and its effectiveness. ZYMOX Shampoo does not contain harsh detergents, pesticides, colorings, or residual petroleum products that might cause unnecessary skin irritation. These and other harsh surfactants used in many other pet shampoos could potentially destroy or disrupt the enzymes in the Leave-On Conditioner.