When you place a white horse in the sun and a black horse in the shade, you are asking for trouble. The camera's dynamic range can't handle the whites and blacks at the same time. Something has got to give and in my case, it was the whites. Poor Jane has her white coat blown out in the strong sun light.
In the second image, I correctly exposed for Jane's white coat while letting not worrying about how Belle's blacks would look. I could get away with it because … well, you can't see Belle in the picture. Just her ears. Poor Belle, she got all dressed up for nothing.