I would do your research on large breed dogs and their nutrition requirements - Everyone kind of errs on the side of caution when it comes to feeding a higher protein diet to a large breed. Which is good, but I am actually of the opinion that we will find out that grain free/higher protein is not the real culprit in growth problems. I know a few large breed dog breeders who wean their litters on to raw - which is the highest protein percentage you can feed, these dogs tend to actually grow slower.