This post first appeared on October 16, 2011
As many people have noted, the term “sabino” has become a bit of a catch-all for a lot of visually different patterns. In this way it is a little like “overo” was ten or fifteen years ago. At the time, the term overo was used to mean “not tobiano”. As the different kinds of overo have become more widely understood, many have dropped overo in favor of more specific terms. But when something doesn’t quite fit tobiano, frame or splash, it usually gets classified – for the moment at least – as some kind of sabino.
In the upcoming book, I attempted to separate out some of the different forms the pattern we call sabino takes. Because only one form of sabino, Sabino1, can be tested at the moment, we don’t actually know if the patterns that are visually different are in fact genetically different. (We already know some things that look virtually the same can be genetically different!) But it is true that some types of sabino can be found in some breeding groups and not others. It’s also true that some of these variations don’t fit the stereotypical “rules” often assigned to sabino. In fact, quite a number of them are likely to be misidentified as something else.
This pony mare is a good example. Many people use high stockings and little or no face white as a clue that the horse or pony has a minimal version of the tobiano gene. (Although it isn’t the best picture, if you look you can see she had some white hairs on her forehead but no other white on the face.) She’s not a tobiano, though. She’s a Hackney pony, which has not had tobiano in the gene pool since the early 20th century.
The one back leg does give a bit of a clue, since the white goes up the front of the leg rather than the side. This overlay illustration of a tobiano and a typical sabino pattern shows how the difference in the placement of white on the leg typical for each pattern.
That is often a good indicator, though it always has to be remembered that “typical for the pattern” is not necessarily the same thing as “always must be so.” The fact that tobiano is not part of the gene pool is a much more reliable indicator. What’s more, this kind of sabino pattern is not really uncommon in Hackneys. In the book I called these Unbalanced Sabinos, because they break the general rule that flashy white on the legs is usually matched with flashy white on the face. As these types of sabinos go, this little mare is actually pretty minimal. There are Unbalanced Sabinos that have extensive body white and very little white on the face.
Unbalanced Sabinos also break the rule posed by some writers that the sabinos have white on the chin or lips. The horse at the top of the post is my old Walking Horse gelding, Master. He had a star and a snip, but no white on his lips or chin. Not only was it unusual to have four white legs without much face white, his leg markings were themselves unusual. The angle on this photo does not show it well, but there was a dramatic difference in the height of his front stockings, which rose in the front to his knees, compared to his hind socks. That was actually what caught my eye when I first saw him, because it is unusual for the front legs to have more white than the hind ones. He also had a belly spot half way between his girth and his sheath.
(And no, he was not a poster child for classic conformational ideals.)
One of the reason sabino variations have been on my mind was this excellent blog post by my friend Sarah Minkiewicz-Breunig. In the post, Sarah talks about the value of taking reference pictures for sculpting. Like Sarah, I am a huge believer in amassing a huge collection of reference pictures. There really isn’t any substitute for looking at hundreds and hundreds of variations of the same pattern. But even more than that, I would recommend the practice of sorting that collection. Nothing helps the eye spot trends like arranging like with like. That was how the different visual categories of sabinos were developed for the book. Stacks of sabinos were sorted into groups that were visually similar. In some cases, I pulled patterns off one body type and transferred it to another. You’d be surprised how often breed type can override your eye when it comes to spotting similarities (or differences) in patterns. Transferring the pattern over to a different body type can force you to really see things. That’s one reason why the illustrations in the book are on generic horse shapes rather than ones specific to the breed or type being discussed.