You never know he may like it a little better bc it is higher quality. I mean I am no Vet but I know that I put Pixie on wellness just for puppy when I got her and I slowly changed the food. I did it like this:
Step 1
Day 1 - 3: Mix 75% old dog food with 25% new dog food.
<LI id=jsArticleStep2 itxtvisited="1">Step 2
Day 4 - 6: Mix 50% old dog food with 50% new dog food.
<LI id=jsArticleStep3 itxtvisited="1">Step 3
Day 7 - 9: Mix 75% new dog food with 25% old dog food.
<LI id=jsArticleStep4 itxtvisited="1">Step 4
Day 10: Feed 100% of the new dog food brand.
<LI id=jsArticleStep5 itxtvisited="1">Step 5
This slow schedule will allow your dog to adjust to the new food without indigestion, diarrhea, or constipation.
<LI id=jsArticleStep6 itxtvisited="1">Step 6
Consult with your veterinarian if there are any problems during this transition period and follow his advice. If you have any leftover old dog food, you can throw it into your yard for the birds
<LI itxtvisited="1">This information is on ehow here is the link
How to Transition to a New Dog Food in 10 Days | eHow.com