This post first appeared on January 17, 2012
I waited to post this because I hoped to find more detailed information, but since that’s a little ways off, I am not going to wait any longer. There is now a genetic test for Splashed White!

Actually, there are three identified genes – SW1, SW2 and SW3. The test for all three is now available from UC Davis for $25. When I spoke to someone at the lab, I was told that the study behind the test was not yet published but that the research was done by the Swiss. Needless to say, a lot of people are really anxious to see that paper! Splash has long puzzled horse color researchers, so hopefully these three tests will help resolve some of the long-standing questions.

This is all really exciting to me. Splash has been the pattern I have had the strongest interest in, ever since I saw the crop-out Welsh stallion The Hot Spot in the late 1970s. Over the years, I have collected pictures and pedigrees of anything that displayed the “classic” pattern. That is, the type of pattern on Journey’s Made to Order, the Morgan mare pictured above. I came to believe that horses like her were homozygous for splash, while horses with one copy of the gene didn’t actually look like pintos as most horsemen would define them. Maddie fits that pattern of inheritance very well, as her sire and dam show. I also came to believe that as the subject of horse color became more popular, and interest in identifying patterns rose, that splash was being over-identified. Or at least, some of what was being called splash didn’t fit the behavior of the original “classic” pattern.

In the book, I described splash as being the “classic” pattern. I put everything else in the chapter on sabinos, making it clear that particular grouping is really just a catch-all for pinto patterns that don’t yet have a specific name. Because so much about sabino is not really known, and because the pattern varies so much, I did break it down into a handful of visual types. Two of those types I called “false-splash”. These were the horses that were getting pegged as splashes by a lot of people, but yet did not fit the pattern of inheritance I saw with the “classic” horses. The best way to describe them (without using all the illustrations in the book, that is!) is to say that one type mimics the bottom of the splash pattern, and one mimics the top. That’s really oversimplified, but with the first “false-splash” what you see is the white coming up from the bottom of the horse, often up and covering significant portions of the hindquarters. They are pretty significantly white, but their faces look like typical sabinos with the wrap-around the profile blaze, chin and jaw. They don’t seem especially prone to blue eyes. This type of patterning is seen in quite a few Clydesdales. The second “false-splash” have the right kind of very-white faces and blue eyes, and they usually have white on the legs, but the white doesn’t travel up high on the body the way it does on a classic splash. They are missing the typical body white.

So needless to say, the idea that there are three splashes is very exciting, because it would be beyond cool if any of those correlated with any of my categories (classic, false1, false2). Right now, with almost no information (and no pictures), it is impossible to know. I am really hopeful that SW1, which the researchers have said is the most common, is in fact Classic Splash. The breeds given as having it all have families with the right kinds of visual patterns, as well as the right patterns of inheritance. It may be that the others look much the same, or it might be that I’ve wrongly categorized those other two types as sabino and they are SW2 and SW3. Or I might have been completely off-base and it’s something totally different! Whatever the outcome, it’s all really exciting. I’d pick being proven out in left field but finally knowing the answer over not being sure any day!

I do hope that many people take advantage of the tests, and that they share the results. The more images we have of tested horses, the better we can define what the Splash patterns look like. At $25 for all three tests, it should tempt a lot of people to see what they have. Usually it is that price per test. I know I took advantage of it! Since the testing on my mare was done at UC Davis, they had her on file. With a few clicks on the website, she was submitted for the tests. I don’t have any specific reason to believe she is a splash, but with an unknown stock horse ancestry it is possible. It would certainly be humbling if I found out I was sitting here with a splash horse all along!

I would also like to encourage any of the blog readers who have their horses tested for this, please share photos and results! I will be posting mine as soon as they are available.

(The picture of Maddie was graciously supplied by Laura Behning. For more information on splash Morgans, Laura’s site is a wonderful resource!)