"... read somewhere in another thread that light-colored poop means your dog isn't absorbing the nutrients, bad food, etc.? As a BARFer, my dogs poop is almost completely white when it comes out, and it soon dries to totally white and crumbles into dust. Yet their diet is really good, all they eat are bones, meat, veggies, a bit of offal here and there, and a few supplements. Is there any truth to this light poop business?"
Hard and very dry, light brown feces that turn white when dried up means that there is ground up bone in it, however if fat is not being digested propely the feces will be also a light brown [but more soft] and might mean that they have a problem with thier digestive enzymes such as amalase and lipase .[ whitch are excreated from the pancrese ]or bile which is made in the the liver and reaches the intestines via the bile duct. So in that case there is either too much fat for the enzymes to digest or that there is a problem with one of the organs listed above.
i had fun lookin at poop all my career as a veterinary nurse