This post first appeared on October 26, 2011
Roan and sabino tend to be catch-all terms for horses that have white hairs or white markings. In the next few posts I wanted to share a few horses that a generation ago would simply have been called roan, but that have white hairs or ticking from something other than the true, dark-headed roan gene. The general convention now is to group horses like that in with the sabinos, but their actual relationship to the sabino patterns is not really known.
The American Belgian at the top of this post is a pretty typical roan-like pattern that is probably a type of sabino. Horses like this lack the very distinct dark points of a true roan, which are usually apparent even when roan gets combined with sabino markings. His legs are dirty, which hide the fact that he does have white feet, but compare his legs to this true roan with a white stocking:
The upside-down “V” formed by the dark points on his front legs, which is one of the hallmarks of the true roan pattern, is particularly visible in this photo. This Belgian does not have those, even though his front socks do not extend far up his legs.
Notice, too, that the roaning not only extends into areas that would be dark on a true roan (like the face and lower legs), but it is quite uneven. His neck, for instance, shows very little roaning. Even more interesting are his hindquarters, which have patches of less intense roaning. For those artists familiar with etching to achieve roaning effects, it looks like the person doing his pattern got bored with the process by the time they reached his bum! These kinds of revertant patches are pretty common in sabino roans.
He also had an unusual roaned patch on the border of one side of his blaze.
I suspect that a lot of the Belgians (of American breeding at least) registered as chestnut roan in the last fifty years are in fact sabinos like this guy.
He isn’t that unusual, as sabino roans go. What is interesting is that it seems possible to get sabinos where there are fewer indicators that the pattern is there, beyond the roaning. There are a number of instances where horses from sabino families have body roaning and a blaze, but no other white markings. In some breeds horses with all-over roaning and a blaze (or having even less white on the face) have been tested to carry Sabino1, the only form of sabino that can be tested at this point. Belgians are not known to carry Sabino1, though it’s also true that testing has not been widely done among many of the draft breeds, with the exception of the Gypsy Horse.
What we call sabino is in fact a lot of different types of patterns. Those patterns can be sorted out visually, as I did in the upcoming book, but it may be that those visual categories include different genetic colors that sometimes mimic each other.