Tag Archives | rabicano

Rabicano versus Sabino


Yesterday I use the pattern on this horse to discuss the way sabino can mimic rabicano. If sabino can mimic the rabicano pattern, then what exactly does a sabino-rabicano look like. Is it any different from the sabinos that have flank roaning and coon tails?

One difference might be the way the roaning organizes itself. Rabicano is known for having a brindled effect. That is a bit different from the diffused roaning that is present on the horse above. Contrast his side with this mare:



In the areas where the white is less concentrated, the brindling is visible. (In my experience with my own mare, whose striping is pictured in the blog header, this trait is often less obvious in photos than it is in person.)


It may be that this trait can help identify the presence of rabicano as opposed to sabino roaning or even the other forms of white body ticking. Rabicanos do seem to brindle more often than other types of ticked horses, though it is hard to know if this is an exclusive trait or not, too.

Another interesting difference with this horse compared to the first one is that the tailhead is more completely white.



Could sabino, which often boosts the white in other patterns, be influencing the amount of white on the tailhead? The frequent assumption is that rabicano is adding white tailheads to sabino patterns. This kind of effect, where sabino amplifies the white of another pattern, is consistent with what we already know sabino does.

This all illustrates the problem with identifying patterns using the tools we presently have. We have pieces of the puzzle, but we do not (yet) have a complete picture. The point at which one pattern begins and another ends is not entirely clear. To make matters more complicated, the evidence suggests that at the more minimal end there is considerable overlap. And at t the other end, the amount of white tends to hide the clues!

Both horses posted are good examples. Not only are they roaned and coon-tailed, but they each have high stockings and one blue eye. Here is the head shot from the mare. (I did not have a good, in-focus head shot of the colt in the first picture.)


Does her blue eye come from sabino, which she obviously has? The white high on the broad side of her neck suggests she also has the frame pattern. Did that give her the blue eye? Is it proof of the presence of splash? Right now we simply do not know for sure. When there are more tests, we’ll probably be able to develop a more clear picture of just where the patterns start and end. But for now it really is just guesswork. Sometimes the breed can eliminate certain possibilities, or more clues can be found by examining production records of a given family of horses, but it is still guessing.

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More mimicry


Horses like this one often get labeled as sabino-rabicanos. The high stockings with their irregular edges and the wide blaze that travels under the jaw are typical of horses with the sabino pattern. The reason many people add rabicano to the description is the roaning on the flank and the white on the tailhead.  Here is a better angle to see that trait.


The trait is sometimes called “coon tail” because the roaning can take on a banded appearance. This horse has banding that is a little more pronounced than the first horse. (It can be even more noticeable on some horses.)


The problem with this is that a lot of sabinos have these traits, too. Both flank roaning and white at the tailhead do not appear to be exclusive to the rabicano pattern. There is overlap between the characteristics of the two patterns.  We can assume that because were all the horses with roaning on the flanks and white tailheads carrying two separate genes, one for rabicano and one for sabino, then the two patterns should segregate in a certain percentage of the offspring. That is, in addition to producing sabino-rabicanos, they should also have some pure sabinos and some pure rabicanos.

Consider the well-known frame overo Saddlebred, Beau Decision. He has a very typical expression of the frame and the sabino pattern together. Not surprisingly, those two genes segregate in some of his offspring.  Here are a few of the sabinos, and here is a pure frame. Another frame, though probably not the only pattern, is here.  (Beau Decision sadly passed away last year.)

That is why many of the horses being called sabino-rabicano probably aren’t carrying two separate patterns; the two patterns are not segregating in the offspring. They should, if the horse really has two separate pattern genes, especially when crossed with non-sabino mates. That would suggest that in some cases, the roaning and the coon tails are part of the sabino pattern. Sabino can mimic them, just as it did with the white sclera in the previous post.

Here is a sabino with roaning right in the area rabicano tends to concentrate.


Here is a full body shot of the same horse. (The top shot was a little overexposed, and I had to adjust the contrast, so she looks more red there.)


She did not have any noticeable white on her tailhead.  But this sabino roan does, completely with the banding. (For those familiar with Paint Horse bloodlines, this particular horse had the kind of sabino roan-splash pattern often seen in the Sullivans Heathen horses.)


This horse had an almost entirely white tail, and white at the tailhead that looked more like specks than individual hairs. (Unfortunately I did not get any good close-us of it.)


This is the same mare from the side.


All of these horses have the kinds of patterns that are routinely described as sabino-rabicano, and yet these same types of patterns occur in breeding groups where the two traits – flank roaning and coon tails – are almost invariably found together with sabino-type markings.  Given how common the traits are, one would expect it to be easier to find true, pure rabicanos. That is, if rabicano causes flank roaning and white tailheads, but not leg or face markings, why are horses like this relatively rare? And why aren’t horses like these producing them?

I suspect it is because those traits are not exclusive to rabicano, and that the pattern is being over-identified.

One of the most frequent questions I get asked about the breed color charts is why so many horses have rabicano listed as “not determined”. That is because sabino is believed to mimic those two traits, so the only way to be sure the horse has rabicano is to see a horse with flank roaning and a white tailhead without white markings – or at the very least without obvious sabino markings. Those are harder to find than one might think!

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