I'm not sure about the Nutro recipe that you are feeding, but I recently noticed that Nutro must have changed the recipe of the Nutro Lamb and Rice Puppy because the original bag I bought had be feeding almost twice the amount for my puppy's size and the newest bag I bought (maybe less fillers now?). Tucker eats less and therefore poops less although he does poop about 3 times before lunch, once late afternoon and once evening. Perhaps the Nutro recipe that you are feeding has recently done the same thing - our new lable has a heart shaped emblem on the bag that say "The Smart Start System..."
I had considered changing to Chicken Soup, but it kind of upset Tucker's tummy so I thought for now we would stick to what we know and try again another time.
Let us know what you try.
Julie and Tucker