I would definatly try a different food, Bakers is one of the worst available, you can spot a Bakers fed dog a mile off by their poor skin and coat! Try one of the brands clare suggested or my personal choice Orijen.

The other thing you could do is feed a totally raw diet, seeing as you are already feeding some raw why not make the full switch over?

I wouldn't give the tablets the vet gave you until you have ruled out food allergies/intolerances or you won't know either way.