Mine eat Pro Plan Sensitive Skin and Stomach.
When I adopted Sierra it took me a few months to find a food that didn't upset her tummy and this was the one! They've been eating it for 6 years.

Last summer I tried switching to Wellness and this was the outcome:

Sore feet for Buddy and a vet bill for me.
I know it's not the best food on the market, but it's the best food for my pups.