According to an article I read, with the exception of foods for dogs with medical issues (liver,kidney,etc.) there is no reason to feed specific life stages foods. This is a marketing ploy some dog food companies use. The reasoning is, most consumers have the tendency to be brand loyal. If they get you started using their brand with puppies, chances are you will continue to purchase their brand throughout your dogs life.
I don't think their marketing departments research very many yorkie owners though. From my own feeding experience and the literally hundreds of posts read here, I believe yorkie owners are not so brand loyal. Many of us have started with a brand, researched and changed brands several times, for various reasons.
If your puppy is healthy now, I wouldn't switch.
