Lots of dogs who have itchy skin and allergies can actually be allergic to the grains used in dog biscuits. Since my mums silky stopped having them his skin cleared up.
My dog recently had bladder stones removed which were caused from ph balance. She lives on the diet I mentioned in my post earlier and filtered water since our water here is very hard. No dried food and only roo jerky as treats. I'm very lucky to have a pet food supplier not too far from where I live who knows where everything she gets comes from