Boston Terrier with sudden dandruff

Question
Hi there!
I'm hoping you can help me with a question about our almost 7-year-old male Boston Terrier.  He's an extremely picky eater and we went through many brands in the beginning trying to find a food he liked.  As much as I hated it, we ended up feeding him Beneful for the last few years because it was the only food he would eat - in fact, while he would refuse to eat other brands at all, he seemed to LOVE the beneful and would devour it every meal time.

On his last vet visit the vet recommended Natural Balance.  She said other Boston owners have raved about it and it helps with the awful gas problems Bostons have.  I liked the idea of giving him a better quality food, so we switched about a week ago, gradually phasing out the Beneful.  

He seems to like the Natural Balance (it's the duck and sweet potato variety), but coincidentally in the past week he's developed really large dandruff flakes on his hind quarters and lower back area.  

I work from home and he's with me all day.  He doesn't scratch at all, which seems funny because the dandruff flakes are so large, it seems like his skin would be really dry.  He's had allergy problems in the past where he's developed ear infections or had yeast in the folds on his face, but he seemed to outgrow those and hasn't had any problems in the last two years or so.  But even with the allergies he never had dandruff.  

Even though he's an indoor dog I'm slightly worried about fleas, but like I said, he's not scratching at all, not even periodically, so he doesn't seem to be itching at all.  

He's not losing any fur, and his coat is nice and shiny and healthy looking other than the white flakes.  Could the dandruff be some kind of allergic reaction to the new food?  I'm worried it'll get worse now that the Beneful has been fully phased out and he's eating just the Natural Balance.  Any advice would be greatly appreciated!

Answer
I seriously doubt that the new food would cause flaking after a week. Flakes are usually the result of infection on the skin causing large pustules to form. Sometimes there is dry seborrhea causing the flakiness.  Check with your vet to see if there is an infecton or something else causing these flakes.