My 9 month old mini schnauzer is currently covered in white dandruff.  It's on both her skin and her fur, even to the tips. She gets groomed and clipped regularly. Can anyone recommend any shampoo/treatment or tell me what's best to do please?

Camrosa's good for scurf. You could also look at her diet. She may need some oil adding as a supplement, or you could try liquidising spinach and adding a dollop to her meals.