Faced with thousands of dog food brands that need to make choices for my own pets, this will be a difficult problem. Which of the dry dog food and wet dog food is better? I prefer dry, what about you?
Be aware that what works for one dog may be disastrous for another. I'd start with whatever the former owner has the dog currently on. If it works - good poo, not itchy, then I'd stay with it. If not, then you'll have to make a change.