Flaky Skin

Question
My 12 week old German Shepherd has flaky white spots all over her black hair.  I think it's flaky skin.  She scratches a lot.
She has been bathed once at 8 weeks.  She is on Royal Canin puppy food.  She also gets a NuVet Plus wafer each day.  Would it help bathing her?  What type/brand of shampoo do I use?  It seems I read somewhere not to bath too often?  

Answer
Feed a decent chow and as little else as possible, seldom if ever bathe the dog, and brush it daily with a soft bristled brush.  You might add a teaspoon a day of liquid cooking oil to its food.  

I might add, most of the Shepherds I see are eating Pro Plan, and I never saw any of them with a skin problem.

If a chow is any good, you don't need to give anything else.  Suppliments can only mess up the careful balance of a properly formulated chow.