My dogs have always had progressively looser poos throughout the day - even on full raw, also on kibble, and also on a combo of both. Patp - you don't have to feed raw to be an expert on dog poo
As long as their main poo in the morning is firm and what I would tend to call 'good' I don't tend to worry any more - and nor does my vet.
Jago's will end up as slush after a long walk - mind you he covers more ground than most other dogs we see so it's understandable
Jarv's used to but he doesn't expend as much energy any more so most often his stay firm all day.
And Jago has also had colitis from feeding raw chicken wings so watch for that too