My Local Walmart does stock and sell Purina Pro Plan dog food and you can also get Purina Pro Plan dog food through Chew.com which may even be cheaper by buying the Purina Pro Plan dog food or any other dog food online through Chewy.com or other online stores.
You can go to Walmart.com and look up your local store and see if they have any Purina Pro Plan dog food in stock at your local store but Walmart does sell Purina Pro Plan dog food.