Shephard with bug bites

Question
My eleven year old German Shephard has scaby lumps on his back around his tale. He is often scratching that area with his teeth. I have had him looked over for fleas and the vet never found any.  Have you any suggestions and have you heard of this sort of thing before.  His name is Boggie and he is half Shephard and half Akita.

Answer
I would recommend that you apply Advantage or Advantix to him even though you are not visibly seeing fleas.  The flea may jump on him, feed and jump off creating an allergic reaction.  This sounds like flea bite allergy to me.  Otherwise make sure you feed him a high-quality, all-natural diet...fish-based would be best to help with his skin--brands such as Verus, Wellness, Natural Balance and Flint River Ranch are excellent choices.