Except for instances of obvious soiling it is best to limit baths to once a week. Be sure to use a mild dog shampoo such as aloe and oatmeal and be cautious not to allow excessive chilling. The more frequent the baths the more likely for dry skin to be a problem. Using a leave on conditioner and giving an essential fatty acid supplement can help maintain adequate oil in the skin. 3-V caps, DermCaps abd Pet Tabs FA are a couple examples. You might take a look at the Doctorpup.com video "My Puppy Got Dirty"