I've been feeding Dax the Nature's Recipe food and I really wanted to get him on something different. I've learned that nothing is perfect and there will always be people who have bad experiences with things that work wonderfully for others, so after reading bad things about everything and good things about the same products, I finally decided to buy a bag of Royal Canin. Now here's my question -- There were so many different kinds (even breed specific -- never heard of a breed specific dog food, but hey. There's a first time for everything), I'm pretty sure I got the wrong one. But I only realized it after I've given him some (thus the bag already being open and me being stuck with it). I bought the puppy formula for dogs up to 20 pounds, which at the time I interpreted "up to 20 pounds" to mean their weight NOW, not their ADULT weight, which I think is what it meant. Anyway, what I'm wondering is what really is the difference? And should I just go ahead and feed it to him anyway? I mean there really can't be that much of a difference, can there? Any help would be appreciated. Thanks!