I have two Scottish terrier puppies and I've been feeding them both Blue Buffalo Puppy Chicken and Rice three times a day. One of the puppies does well and doesn't have any tummy problems. My other puppy only has a "regular" poop in the morning before breakfast. Any other time I see him poop, it's anywhere from the consistency of soft serve ice cream to liquid. I'd love to get some advice on how to proceed with him. Should I switch him to a different brand or just add something like pumpkin to his food? If I need to switch him, do I do this all at once or slowly over a few days? Any assistance would be greatly appreciated!!!