It's very important to wash your dog! It keeps oil from infecting your dog;s skin. But even though washing is good, too much can dry up their skin and it split and bleed! Ask the person you are dog sitting for if their dog/puppy has any special kind of soap you should use. It could be very dangerous if you use the wrong kind, it could make their dog/puppy very ill! Also remember to wash the soap out of the dog's fur,cause if it dries on their fur it can irritate them very much. So remember.......A clean dog is a happy, healthy dog!