True,my main issue with Pedigree besides it's low quality ranking is the loose,messy stool my dogs have produced after eating it.
Interesting, I guess just like with fish food different dogs will have different reactions/results with different foods. Except on the rare occasion I had to switch to other brands (which would be natural for a dog to have some loose stools), I never really had that problem with any of my dogs (Westie-Poo that lived until 17/18; 2 Labs, one who lived until 14, the other 12 (both put to sleep do to back legs going out); and our current pup, an 11-yr old Spanish Hound).
That said, who knows, maybe with better food they would have lived even longer. To me Pedigree is kind of the Hikari of the dog food world -- it works pretty good but there are surely better.