I took Duke back to the vet and after finishing meds for yeast, bacteria and steroids, everything is healed, and I'm feeding him only food with no corn, wheat or beef. He looks much better, not itching anymore, but hair is extremely thin on his sides and skin on his back and sides is black. Is it supposed to be black? His tummy is normal pink-looking skin. If it's normal to be black, I guess he's ok, just need to know if I'm still dealing with a skin condition. Thanks for all the help!