In the comments on this post, I mentioned getting updated pictures of Prince, the palomino with all the Bend Or spots. I thought that he was more heavily spotted than last year, and after comparing earlier pictures I believe he is. These aren’t the best pictures since I didn’t have time to take him out of his shady pasture. He’s also a bit of a love sponge, so getting far enough away from him to get his whole body is always a trick. (I have almost as many fuzzy close-ups of his nose as I do of Sprinkles.)
In those comments, Sarah mentioned that the Bend Or spot on her Arabian, Dar, had the same three-dimensional quality that Sprinkle’s appaloosa spots have. I had a theory that perhaps the black hair grew at a different rate. But Prince’s spots seem to disprove this idea because they are flush with the rest of his coat. Here are some close-ups.
So perhaps it isn’t about the color of the hair, but rather the density of the pigment. Appaloosa spots are densely pigmented. This is particularly obvious when an appaloosa has self-colored spots on a dark background. Many Bend Or spots have that same appearance, and those might appear three-dimensional in the winter. Prince’s spots are, however, clusters of black hairs mixed in with his normal color. Some of the spots have a higher percentage of black hairs than others, but they are all something a of a mix. If I had to guess, I would think that Prince was genetically a sooty palomino but that something was directing the black hairs to form spots rather than more usual patterns (dappling or all-over dispersion).
Rebecca Turner sent me some pictures of another odd expression of sooty palomino, and I’ll see if I can’t get permission to post those, too. He was another really unusual horse!