You dont, you got to remember as an animal you don't let water or dirt soak to the skin so their fur is a natural repellent. As long as the water does not soak through to the skin Its not "dirty" Its no different after life and death. Little water and dirt you just let it dry on the pelt and brush it off once fully dry, if the fur is just so lightly damp shake it off set it aside and let the air finish it, then take a brush and fluff it up again and walla Clean again.