I was just about to post the same problem!
Bella has got the worst dandruff ever!
Her coat is naturally really short so I dont have to brush her at all. Although I do to get her used to it. She is also 10 months old.
I looked at her skin and its like really dry skin. No patches just flakey skin which is leaving her with terrible white scurf!
I feed her Burns so I doubt its her diet, and only natural treats like pigs ears and dried (yuk) tripe.
We bath her about once a month. We used to bath her most weeks during winter but its worse since we lessened the baths.
I was using a puppy shampoo but changed to a tea tree one so thats made it worse rather than better
Any advice would be welcomed