Katie-
It isn’t very challenging for a company with a veterinary nutritionist and multiple veterinarians on staff to be able to formulate a food that is appropriate for both sensitive skin and sensitive stomach. Salmon tends to be a good protein for dogs with skin allergies (the main protein in Pro Plan Sensitive Skin & Stomach is salmon) and the right types of fiber and % of fiber can help dogs with sensitive stomachs. Plus limiting the amount of ingredients in the food, adding probiotics to the food and having ingredients that are easy on the GI system.
As someone with a dog with both skin allergies and a very sensitive GI system, I can attest to the fact that Pro Plan Sensitive Skin & Stomach was a miracle for my dog. We only switched when we found a cheaper food of similar quality that came in a larger bag.
