Ancient DNA studies shows that "leopard spotting" was one of the phenotypes of Paleolithic horses in Europe, as shown in some cave paintings.
I don't much care what this says about the painters, but I think it's interesting commentary on the pre-domestication phenotypes of horses. We generally think of coat colors and patterns as being more variable in domesticated animals than non-domesticated, since animals may be bred for a certain look, or they may react to the relaxation of natural selection against brightly colored or patterned animals who were too easily spotted by predators. Had I thought about the issue, I would have assumed leopard spotting was an example of coat variation that occurred after domestication, like spots on dogs. Well, I would have been wrong.