How does it work?
Remember that medical jargon we just mentioned? Well strap in because here is the explanation of how this all works. It all starts with the placenta, which has a massive amount of blood inside it that moves around. Now, all that blood that is broken down inside the uterus after leaving the placenta is turned into Biliverdin.
And in this case, its green color was somehow able to leak into the amniotic fluid or sac that encircled the puppy fetus inside Rio. Because of this exposure, its hair color was altered while it was still a fetus. So the placenta of that particular puppy was abnormal and allowed for this invasion of the biliverdin pigmentation. Still with us?