Well as a lot of the food you are feeding is filler more comes out than gets digested.
You may find a premium food from a pet supply store will do better as you can feed less of it and less is waste (vs nutrition). Foods like Canidae, Bil Jac, California Natural, Blue Buffalo, Wellness foods etc all may do better for you than what you are now feeding.
Pups do produce more stools than adults do as they are less efficient in digesting food too so that could also be a part of the problem.
You can compare what is in dog foods here
www.naturapet.com/display.php?d=comp-wiz
you may be surprised what is in some of them!
Hope this helps you!
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