I am considering switching our new puppy to IAMS or Eukaneuba. I really want my new dog to eat a diet that is healthy and free of chemicals and preservatives. What is the highest quality commercial dog food available?

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I am trying to switch over my puppy from PMI Exclusive Chicken and Rice Puppy to Before Grain Chicken. I am doing it gradually and I wanted to make sure that it was a high quality dog food. Any thoughts?
Thanks!

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