In my opinion, you do NOT want to feed your dog grain free dog food. A few years back the FDA sent out an alert that there may be a link between grain-free diets and a diagnosis of dilated cardiomyopathy (DCM). It was first noticed in Golden Retrievers. It was found that DCM was reversed when the grain free diet was discontinued.
I feed my lab/golden mix dogs Purina One. It has the shredded bits. They seem to keep them more interested. They really like it and are doing great on it.
There are several articles and FB pages about the issue.
Is Grain-Free Dog Food Bad?
Good luck to you!
