The condition that Azygous is describing is called starve out. The body gets so depelted that there are not even enough energy reserves for digestion. Similar to the state of anorexia nervosa which gets to the point that even if the person so affected tries to eat, her body is so depleted that she simply can't digest, and the body systems shut down. At that point, the only way to save that person's life (if it's not too late) is through intensive IV therapy. This is what PND does: it provides that nutrient boost without having to be digested. It gives just that little bit of oomph to kick start the digestive system so it can start functioning as it needs to. ALL of my chicks get PND. It doesn't matter if it's a weak chick, suffering from shipping stress, or the chick hatched in my incubator: the one that karate chops her way out of the egg, and spends the next 24 hours playing egg soccer in the bator, and climbing the walls.
