Welcome to YT and congrats on your new puppy. I think the advice on switching foods right now is spot on. Your baby is young, actually much to young for a yorkie puppy to have been separated from his miner, to mess with a good thing. If the pup is eating, keep feeding him what you are feeding him. Just keep in mind, and start researching food as there are better choices out there.
As far as shampoos go, a good one that is easy to find is Bio Groom's Fluffy Puppy. Here is a conditioner that goes with it (I think, it's been a while) and you can easily find the shampoo at PerSmart. Just remember to rinse thoroughly after way bath. Let me go back and read your post to see if I have any more insight to share with you. Feel free to ask more questions.
