Nutritional wisdom is the concept that an animal somehow innately knows what nutrients its body needs, and also where to obtain them. For example, if your body were low on potassium, you would instinctively know to eat a banana. And you thought those banana cravings were just evidence in support of the "Man-from-monkeys" evolution theory.
This always comes up when a dog has eaten some bizarre or unpleasant substance, such as cat poop. Today, I performed an ovario-hysterectomy on a young Golden Retriever. When I checked her abdomen during the surgical prep, I thought I was feeling a urinary bladder full of stones. It turned out to be her rectum, which was full of pea gravel.
The dog’s owner can be predicted 100 percent of the time to ask, "Do you think there’s something missing in his diet?" Well, let’s look at the ingredients on your bag of Science Diet puppy food. By golly, you’re right: neither cat poop nor rocks are listed anywhere on the label. This dog has a granite deficiency and has made her way unerringly to a pile of igneous rocks. Or wait! Maybe it’s a limestone deficiency and she has eaten sedimentary rocks. But wait! What if she can’t tell the difference? What if she’s deficient in sedimentary rock, and has eaten metamorphic rock instead?
Dogs just eat anything that can’t get away from them. When someone says that an omnivore will eat anything, they usually mean both plant material and meat. A dog is an omnivore’s omnivore. He will literally eat anything. If it can’t get away, he’s going to eat it. If he only vomits it up twice, he’ll probably eat it a third time. It doesn’t have to be tasty (from our point of view), much less nutritious. It doesn’t even have to be digestible. It doesn’t have to feel good (like the patient who ate the Brillo Pad… twice). I guarantee you that all today’s patient derived from her meal of gravel was that good feeling you get when you swallow a handful of rocks (and that cool clinking noise it makes when you go poop, of course).
Despite our harrowing experience with the pet food recall of late, name-brand commercial pet-foods are going to be a lot better balance of nutritious ingredients than what most dogs would pick out for themselves foraging. How well do I recall the dog-food ad "…with more of what your dog likes!" I envisioned dumping out a bag of dried toads, cat poop, possum vomit, and dirty kleenex. I bought Science Diet instead.