Yellow Lab Constantly Scratching

Question
My nearly three year old yellow lab will not stop itching/biting her self. She is on a strict duck and potato diet which cleared up her rash and we're still giving her fish oil and benadryl with her meals (in the morning and at night). The scratching seems to have gotten worse with the winter months. She seems miserable and I want to help but don't know what to do...

Answer
Is the diet, Benadryl, and fish oil the vet's idea?  I question the fish oil.  While it may be good for our cholesterol, it is completely deficient in the linoleic acid dogs need for their skin and coats.  If I thought a dog needed more oil, I would give it liquid cooking oil which is usually corn oil, one of the richest sources of linoleic acid.  

If you are bathing it, cut the baths out.  Brush it everyday with a soft bristled brush.  Far more pleasant for both man and beast, controls odor, and stimulates the dogs natural oils.  

Humidifying the house might help both her skin and yours.