In the comments section of the previous post, Jo-Ann Ferre mentioned mottling on non-greys, which is also unrelated to appaloosa patterning. That reminded me of one of the pictures in the upcoming book, of the early 20th century Percheron stallion Keror. He was a prize winner in his day, despite the extensive loss of pigment on his face. I’ve seen this on a wide variety of breeds, but whatever the cause it does not seem to run in families or be passed along to offspring. Perhaps that is why breeders have been willing to use stallions like this in years past.
I also apologize for the delay in posts and in replies to private questions. I am slogging through what I hope are the last revisions to the book, so that is consuming the lion’s share of my attention. I should be back to more regular posting in a few days.