I watched it now.
I've found family guy to be pretty ok, decent television as far as television goes. The storylines aren't much to look at, and it does take a big ol' pile of "influence" from traditional family sitcoms (Yes, The Simpsons too), but I find the comedy gives me a few laughs, just because of its sheer idiocy. And when it comes to a cartoon like FG, Simpsons, Futurama or South Park, I'm not in it for the story, I'm in it for the laughs. If I laugh, good, if I don't, bad.
But that episode was just crap. A dog eating a baby's poo? I'm from the internet, so I'm not offended, but I'm not amused either. There's nothing funny about it, it's just dumb and boring. The whole episode is spent in the same locker, where I assume some sort of heavy dialog and strong emotions were supposed to take place. Watching it, however, was like watching some old Monty Python sketch, except this time there were no "police" to come and stop the silly and ludicrous joke with no punchline.
The whole thing, for me, was finally ruined when the door opens, and Brian just walks out, carrying Stewie, without saying a word and nothing happening. It sort of gave me the impression that the writer was trying to make the cartoon comedy equivalent of a contemporary and unorthodox movie, like 12 Angry Men or Rear Window. A noble task in which he horribly failed.
The musical pieces have always been FG's worst part, by a large margin. I watched the first one, and gave up.
All in all, I just found it a waste of time.