After what felt like an eternity, the vet finally looked up and smiled, exhaling a massive sigh of relief. She assured the terrified family that the puppy wasn’t toxic, sick, or deformed. In fact, he was a completely healthy medical miracle. The vet explained that the bizarre coloring was caused by an extremely rare biological phenomenon involving a bile pigment called biliverdin.
Biliverdin is the same chemical compound that causes human bruises to turn green as they heal. In incredibly rare instances, this pigment reaches unusually high concentrations within a puppy’s individual birth sac, mixing heavily into the amniotic fluid. Because the puppy’s natural fur color was so light, the fluid acted like a permanent dye, staining every inch of his coat while he was still in the womb. The vet then dropped a final bombshell: “Globally, there are only three other documented cases of this ever happening.”