I think its important to look at the ingredients of the food and see what's in it. If I see the words 'by product' I stay away from it. Whether its the first, second or even tenth ingredient.
I finally found a brand of dog food that uses all natural products no corn or grain at all (except for brown rice) and I mainly use their dry food but they have a wet food range that are stews for dogs and you can see the bits of meat, the peas and potatoes etc...
What brand is that Boosho? I'm interesting in trying new grain free brands for my girl.