[theBCnut]

I would play it safe and treat him like a large breed, there is no harm to a medium breed from eating a food that is appropriate for large breeds. Great Plains Feast is too high in calcium, but Earthborn is a good food. Your vet is lacking knowlege about AAFCO profiles, a food that qualifies for the Growth profile can be labeled for All Life Stages, therefore ALS foods are Growth foods.