That 30% crude protein sounds high. I like to look more at the dogs that are eating the food, than the ingredients. I recently did some looking in response to a question on another site. The asker was concerned the relatively expensive chow he was feeding was only 19% crude protein. I suspect that if the protein is high enough quality, the chow needs less. Such a chow may have more carbohydrates.
I have the benefit of having seen thousands of healthy young dogs eating the same Pro Plan as I feed. Having seen them, I don't need to look at the ingredients.
Dry food is actually better for dogs, giving the teeth and jaws the work they need. At least it would if my Labs actually chewed it rather than inhaling it.
I wouldn't be concerned with the wheat gluten causing the problem in this case. I forget if the problem with Diamond not long ago was any one ingredient. The next problem could be bad barley.
Most dogs can be trained to eat dry food. You can find a cure for picky dogs in the sticky ''My dog won't eat'',
http://www.askmehelpdesk.com/dogs/in...tml#post254171