I had seen a posting on Facebook of a yellow Lab that had a black band around its midsection. Then, today, I saw this photo posted.
The explanation given was that the animal was genetically two animals ... both black and yellow.
One of the comments on the photo was:
A subsequent comment clarified that the chimera dog can be fertile, but will produce either black or yellow offspring, not another chimera.A chimera is not a mixed breed dog. It happens when two separate embryos fuse together very early on and become one animal (or human) with two distinct DNAs. It can't be duplicated or bred.
Another comment indicated that this fusing of embryos may occur more often than we know, but if both embryos were yellow (or black) we wouldn't know that the fusion had taken place.