My dog had the same problem, fisrt po of the day great, then sloppier and sloppier till a mess; also often diarrhea
it was the rice in the kibbles, I switched to a no-grain no filler food and he is ok.. the last poo of the day is sometimes a bit softer, but still easy to puck up.

and yes, raw chicken wings to clean up his glands, never done , but many do and it works.

I hear a lot of puppies have the same problem, stools runnier and runnier throughout the course of the day.... makes me wonder