Have you tried wiping his paws after he comes in from outside (with baby wipes)? That may help if it is allergies to grass or other things outdoors. Solid Gold is a great food with little or none of known common food allergens.
What kind of shampoo are you using on him? Some pups have a difficult time with various shampoos as well?
Hope your little guy gets some relief soon.
__________________  Sissy & Angel |