We just got a Beagle puppy. He is 10 weeks old now. We have had him about a week now, and have been feeding him Innova Puppy food. His stools are not mushy, but they aren't completely dry/firm either. His stools were actually better on the Purina Puppy Chow the breeder was feeding him. How long will it take to determine if the Innova agrees with him vs. something else ? What's a good trial period ?