Dark dog dung is a matrix, a sponge if you like, of fibrous or calcium-rich material filled with other wiaste that is coloured by porphyrin breakdown products of haem from blood and muscle and other foods. Porphyrins tend to be intensely coloured pigments, so they commonly are dark in combination. When rain leaches out the soft stuff, the white mineral-rich stuff remains behind. In the veld it is valuable material for tortoises and other mineral-hungy animals.
What with our increasing distaste for falling on our backsides and having to clean up afterwards, not to mention the ambient smell, we are less tolerant of canine calling cards than we used to be, and the stuff doesn't last long enough to weather to whiteness.
Furthermore, a really durable sponge requires a very bone-rich diet. Pet foods nowadays are better balanced diets, so they don't contain as much of an excess of apatite as most animal food does, so they don't produce such lasting faecal monuments. Other dogs feed on scraps if they are lucky. Such scraps are as a rule neither bone-rich nor balanced, so they seldom produce bony turds, unless there were a lot of digestible bones in the food, in which case it might produce not only bony turds, but severe constipation.
The really unlucky dogs belong to such vegans as insist that if animal foods are bad for humans, they must be bad for pets too. They accordingly abuse the poor beasts with diets that would make them liable for child abuse if they inflicted the equivalent on children. Vegetable diets are not only badly balanced for dogs and cats, but often actively poisonous, such as oniony or methylated xanthine-rich foods like chocolate.
But the turds of such victims of abuse leave no skeletons behind. They have none to leave.
Savory thoughts?
Cheers,
Jon
