I can answer that...
Dog turds are no longer white mostly because of the processed crap that we feed them at the behest of pet food manufacturers who maintain it's the best thing to give them for a healthy diet.

It's not.

About a year ago we started feeding our dog on the BARF diet (or bones and raw food, or even biologically appropriate raw food). This consists of raw mince, chicken wings, beef and lamb bones, tripe, and liquidised vegetables (but only certain kinds - potatoes are a no-no, for example). the principle being that dogs are naturally scavengers and will eat this sort of stuff in the wild.

She's never had as much energy, or been as healthy in her life. And because her diet contains raw bones every other day, her shit rapidly turns white after a day or so...

It also doesn't stink, or have the consistency of melted chocolate.
( Davros' Granddad a voice of calm reason in a world of spastics., Fri 18 Apr 2008, 17:00, Reply)