Welcome to YT, and congratulations on your new puppies!
Johnson's Baby Shampoo can be very drying to yorkie skin, which could cause them to itch. I'd recommend using something specially made for puppies from now on. Petsmart and Petco carry Biogroom which is a pretty good brand.
Iams is a very poor quality food in my opinion (plus I detest it because of their well documented history of animal testing and abuse
). Petsmart &/or Petco will carry Wellness, Blue Buffalo and a couple of other good brands. If you have an ag/feed supply store nearby you can look for Nature's Variety, Taste of the Wild, Wellness, etc. I'm sorry - normally I can name several good foods but my mind's a blank this morning.
Good luck with your new little ones!
Bonny
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He is your friend, your partner, your defender, your dog. You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion. -- Author Unknown