Belton patterning


In yesterday’s post, I included Audrey Crosby McLellan’s mare, AC’s Painted Lace. The belton spots are pretty obvious on her face, and I wondered if there were similar spots on her white legs. Audrey was kind enough to provide pictures that show them very well.

These first two images are with the lower legs clipped, so they show the spots very clearly. Like the spots on the faces of the previous horses, they are very round and have the same kind of halo effect where the underlying dark skin is wider than the colored hair.

Those images show the markings very clearly, and these are good shots of wet feet to show what is going on with the hooves.

Right front foot (front and back)

Right hind foot (front, side and back)

Left hind foot (front and back)

These pictures show how the color is concentrating down around the hoof. This kind of density in spotting is often seen in tobianos, where the cat-tracks cluster around the hoof. This gives some tobianos surprisingly dark hooves. It is also seen in some belton dogs. They have heavier spotting on the legs (and face), but it increases still more at the toes. Here is a tobiano with that kind of spot concentration, and an inset image of an English Setter with the black-toed belton look.

I have no idea if the actual mechanism behind belton dogs (T, or Ticking) is even similar to these kinds of spots on horses, but the visual similarities are striking.

I would also add that posting unusual horses to the blog is a lot of fun, because it often results in readers sending in images of their own horses, or horses they have encountered. Just recently, someone sent a horse that is truly strange – and it takes a lot for me to call something strange! I am going to use the leg spotting as a jumping-off point to talk a little about cat-tracks, and then move on to my strange example. So stay tuned for some cool stuff!

Advertisements

The above image of a belton patterned face is from the contents page of the most recent Paint Horse Journal. I didn’t notice the title until I scanned it so I could add it to my research files. It certainly does seem that lately there is a horse with this type of patterning “in every issue”!

The horse pictured is the Paint stallion Hes Stylin. He is a good example of the type of belton ticking that seems to be linked with the presence of the frame pattern. Like the pattern in some dogs, this type of dark ticking concentrates more heavily on the face, where the spots are more numerous and generally larger than on the body.

(English Setter picture courtesy of Wikimedia Commons.)

Since making the initial few posts about what I called belton patterning (for lack of a better term, since “ticking” already means white hairs in the coat), many people have sent pictures and links to horses with these kinds of markings. I have also begun noticing the less dramatic versions that I had previously overlooked. The more I see of ticked horses, the more I believe that this particular type is probably linked to frame. That doesn’t explain a horse like Vision Morinda, or the more heavily cat-tracked tobianos, so I suspect there is more than one cause of dark spots on markings or patterns. The frame overos with belton patterning, though, seem to have a pretty consistent look.

The spots are very round, and often have more colored skin than colored hair, which gives many of them a ghosted or haloed appearance. This type of effect is noticeable on the cluster of spots close to Hes Stylin’s left eye.

The white patterning on the body does not really show a lot of these round spots, though most have had some. I’ll return to Gump, the first horse I posted, to show both sides of his pattern. The round spots on his face contrast quite markedly with the ragged nature of his pattern. The link to Hes Stylin (above) shows a full-body picture, and he has the same kind of contrast between the torn outline of his pattern and the regularity of the spots.

I apologize that I don’t have a better photo of Gump’s left side. I try to get conformation shots of both sides on patterned horses, but sometimes the opportunity never presents itself. It’s not a flattering picture, but that left shot does show how much clear white there is on the body pattern relative the the spotting on the face.

Gump does have some belton spots on his lower legs, though they are not as pronounced as on his face. Most dogs that have this type of belton pattern have bolder spotting on the lower legs as well as the face. The image of this English Setter puppy (also courtesy of Wikimedia Commons) illustrates that effect, though the underlying black-and-tan pattern makes her feet look paler because the base color there is tan.

Because frame overos do not typically have a lot of white on the lower legs, it is hard to know if the spots would concentrate there or not. In fact, many of the examples I have encountered or have been sent have no white on the legs at all. Here is a mare I photographed at a fun show last fall. A different photo of her appears in the book to illustrate the frame pattern in what is probably its pure form.

Her legs are all dark, but here is her face. The spots are not nearly as pronounced on her as on Gump and Hes Stylin, but that seems to be true of most of the chestnuts with these types of spots.

What is interesting is that this mare also has what looks like a large occluding spot above her right eye. For that matter, it is possible to think of the patch over her eye, and the one across her muzzle, as occluding spots. If you look at Hes Stylin up at the top of the post, he has a similar set of patches above his eye, too. A similar spot is present on this Paint cross mare, Hechzeba, shared by Audrey Crosby McLellan of ACC Photography.

She is tested positive for frame, but has no body white (or leg white) to show any further spotting.

Audrey also sent a link to pictures of her own mare, AC’s Painted Lace, who was also tested to carry the frame pattern. Notice how she has a patch over the eye and on her nose that are quite similar to the earlier mare.

In photos it looks like Lacey has some spotting inside her socks, but even her face spotting is more subdued than some of the others. It may be that is due to other white patterning, since some white patterns (like some forms of sabino) are known to amplify the white on the horse at the expense of colored areas. It also might be that this particular kind of spotting is just concentrated on the face. Until there are more examples with leg white, it is hard to know for sure. And even then, it is hard to know if the factor that put the white on the legs (where it is usually missing on frames) might not also erase the spots there. That may be what happened with Hes Stylin, since he has what appear to be unspotted legs.

(Hes Stylin is also interesting in that his is the combination of frame with another pattern that is most often mistaken for tovero. Although the dark areas fall in such a way that it is an easy mistake to make, his sire is an unmarked Quarter Horse (Kids Classic Style) and his dam is a overo mare (Shesa Scotch Bar Doll) from a long line of overos.)

One of the most interesting aspects of white patterns, at least for an artist, is whether or not they overlap one another or interact with each other (and other modifiers). Perhaps because most techniques involve adding – or sometimes removing – layers of color, it is only natural that artists tend to assume a layering relationship. What is appears to be true is that patterns typically have a complex set of interactions. For example, there is good reason to believe that some of the sabino patterns (like the one seen on the horse above) interact with whatever mechanism produces ordinary white markings by amplifying the white in those areas. Meanwhile both the markings and the sabino patterns appear to interact with the base color.

Simple layering seems to be far less common. That is one reason why some forms of snowflaking (like the one in this post from a few days ago) are so interesting, because it appears that some types do overlap existing patterns. I suspect that overlapping white spots are behind the really unusual “jigsaw” leopard Appaloosa mare Dazzling Vision Spot. More common, though, are overlapping dark spots on the face. In dogs these are sometimes called Blenheim spots, for the red and white pattern in Cavalier King Charles Spaniels where the markings are considered desirable. One is visible inside the blaze of the red and white spaniel in this nineteenth-century copy of a Landseer painting.

The horse at the top of the post has a similar spot in the top corner of his blaze. In horses these inset spots more often appear offset rather than centered on the blaze. This can give the the top of the blaze a scalloped look. Since the one in the picture is set a little further inside, it bisects the blaze so that there appears to be an irregular section of disconnected white. That white is probably not a separate marking, but rather the remainder of the blaze that the overlapping colored spot did not cover. The tinted areas in this photo show how this works.

I have shaded this Paint Horse’s broad blaze blue, and the imagined overlapping spot bright pink. The area where the colored spot overlaps the blaze is purple. On this horse, the disconnected white this leaves is much smaller. I have called these colored patches occluding spots, since they cover (occlude) part of the white face markings. If the spot is large enough, the result is what is often called a badger face.

Some badger-faced horses have spots large enough that the only thing left of the blaze are small, detached segments of white. Here are some good examples of that: Akhal-Teke1, Akhal-Teke2, Paint Horse, Thoroughbred and another Paint.

The separate nature of occluding spots is even more apparent when they occur when white patterning has completely removed the color from the face: Paint, Gypsy Horse, and another Paint.

I suspect that the horses pictured so far have something similar going on with their face markings, with just slight variations in scale and placement. I do not believe every dark spot inside a face marking is an occluding spot (or minimized badger-face marking, if you prefer). This guy is perhaps a good horse to look at what are probably two different things altering his face marking.

The most obvious change to his blaze is what looks like two or more occluding spots breaking it into two pieces. If you look further down his face, though, his blaze begins to break apart into round spots right behind his nostril. Because the scale and character are rather different, it is my suspicion that there are different causes for the two changes. What is happening close to his nose looks a bit like the way sabino degrades the edges of markings. This Belgian has a more roany version of what is probably the same type of thing.

Here is another horse that has what I think are two different things going on as well. Along the upper edge of her blaze a mid-sized occluding spot has cut off most (but not all) of the corner of her white marking.

Then there are small spots of color inside her blaze. I suspect that is Belton patterning. Since first posting about the possibility of dark ticking separate from the actions of the different patterns, many readers have sent leads on horses with this. That will be the subject of the next post. (Previous posts on Belton patterning, for those missed them, can be found here, here and here.)

This is “Gump.” He’s a Paint Horse that shows here in the Carolinas, and is the horse that first had me wondering about the possibility of a dark ticking pattern that was separate from any of the white patterning genes. As you can see, he has quite pronounced spotting on his face much like one might expect to see on a leopard. The problem is that were he actually a leopard as well as an overo, those spots would replace his bay areas, not his white areas. (For those just joining the conversation, the two previous posts explain this in much more detail.) I suspect those familiar with leopard patterns would also recognize that there area around his mouth doesn’t look right for the appaloosa pattern, either. It is too “clean”, with the spots and the white very clearly defined. If you cover his face so that just his muzzle shows, he looks like a pinto with “kissy spots” and not a leopard appaloosa.

So he is just a pinto. Here is a side shot to show the rest of his pattern.

As this picture shows, he’s a frame overo. That white on the side of the neck and again on the side of the body are classic placements for that particular pattern. He probably also has one of the sabino patterns, since he has high stockings in the back. Frame does not typically add white to the legs, so frame horses with white legs are usually carrying something else in addition to frame. Since the various sabino patterns are widespread in riding horses, and especially in stock horses, it’s the most likely cause.

What struck me about Gump is that his pattern has a torn, angular look, which is quite different from his extremely round ticks.

There is spotting on his leg white, too, though I did not manage to position myself for the best lighting in this photo. Like the spots on his face, these are round even though the rest of his stocking goes up in ragged angles.

The character of the ticking and his pattern do not match.

That is particularly interesting to me, because most of the pinto patterns interact with one another. They don’t just overlap one pattern on top of the other. The presence of one tends to effect the appearance of the others. That overall influence gives most patterned horses a harmonious look. It also complicates matters for those of us interested in teasing apart and defining the different patterns, when the action of one mutation changes the actions of a second, unrelated mutation. Sheila Archer, of The Appaloosa Project, refers to this as patterns “talking” to one another. I have always liked that way of phrasing it, and would say that much of what I find most interesting about patterns these days revolves around those “conversations” between the patterns. The discordant patterns on Gump say that whatever is causing his ticking, it doesn’t seem to be “talking” to the rest of his patterning. That would at least suggest that it is something separate from whatever is causing his pinto pattern.

Gump sat in my “weird stuff” file for years, until last month, when a Facebook friend linked to this horse. When I first saw the image as a thumbnail, I assumed someone had found Gump. The ticking and even her base color is that similar! But that’s not Gump. That’s an Australian sport pony named Haley’s Comet.

Around the same time, another horse came to my attention. Her image was used on the header of the Paint Horse Connection, a quarterly newsletter that goes out to American Paint Horse Association members, and in an article in the Paint Horse Journal.

Like Gump, she is a frame overo, but without the sabino-type leg white. And like Gump, she has the spots that are very concentrated on her face, compared to the spots on her body. Because her body has broad areas of white patterning, it’s even more striking on her.

That was what made me think of the Belton pattern in English Setters. They sometimes have that same kind of larger, more concentrated spotting on the face compared to the body.

They aren’t all like that. One of the most interesting thing about the ticking (Belton) pattern in dogs is that it does have a lot of variation even within a single breed. But on a horse this kind of concentration on the face is quite unusual. Heavily concentrated dark ticking is odd in horses. Having it more pronounced on the face is stranger still.

You might notice that these horses all have a similar spotting arrangement, but that arrangement is rather different from Vision Morinda, the horse posted previously. Her ticking is more uniform, smaller and denser. It is hard to know, with so few horses like this, if these are variations on the same trait, or different things entirely. But having seen a handful of horses like this now, I know I’ll be looking at ticking more closely in the future. And certainly if any readers find horses with interesting spots inside markings or patterns that don’t fit what might be expected for a tobiano or one of the overos, please pass them along!

In the previous post, I talked about the two things that cause horses to have small dark spots on a white background. The first was the leopard pattern (Leopard Complex + Pattern1) and the second was the homozygous tobiano pattern. In this post, I want to talk about how dark spots on a white background are different in dogs.

Dalmatian dogs look like leopard appaloosas. It’s the same white background and the same small, round spots of color.  But Dalmatians are genetically very different from leopards. In fact, they have a lot more in common with the homozygous tobianos. That’s because they are “pinto” dogs. They just happen to be missing (or at least mostly missing) their dark patches. In fact, if you can imagine someone starting out with a classic tobiano horse – dark head, large round areas of color on the body – you have a good idea of what the basic piebald pattern is in dogs. In fact, in some countries the name for tobiano and the name for this pattern in dogs is the same: plating. Plattenscheck, platenbont – plate pinto. It makes sense, since tobianos have large “plates” of color on a white background. These dogs do, too. Or at least they started out that way. Here is a popular sire of English Setters from a little over a century ago.

His pattern is very reminiscent of tobiano. But breeders did not care for the patches, so they began breeding away from them.

In dogs, this kind of pattern is often called “extreme piebald”. It is still a “pinto” dog, but it doesn’t have a lot of color left, even on the face. English Setter breeders were not alone in this preference. The Dalmatian breeders were selecting for the same thing. They did not want patches, or even dark ears. They wanted all-over round spots.

Those round spots, which are visible in all three of these English Setters, look a lot like cat tracks to someone familiar with tobiano. What makes them different is that they aren’t actually part of the plating pattern. They are a separate thing entirely. For English Setters and some of the other sporting breeds, that’s the “Belton” pattern. The more technical names for it – ticking and roaning – are unfortunately for us horse people, already taken by very different patterns. So for now we’ll just use Belton to avoid making this any more confusing.

Belton adds dark spots of color to the areas the piebald pattern leaves white. What dog breeders have done is manipulate the scale and spacing of those spots of color. All three dogs at the top of this post have what are believed to be variations on this kind of patterning. The English Setter to the left is of course the original Belton pattern. The Dalmatian in the middle is likewise has a Belton-type pattern, but he also has some kind of modifier that has made the spots larger, rounder and more distinct. (Some of the distinctive nature of his spots are, of course, because he is a sleek-coated dog compared to the setter.)  The Australian Cattle Dog at the end has a Belton-type pattern that was modified to the other end of the spectrum, with spots that have gotten smaller, less round and less distinct. In some breeds, this is what is called Roan. There is some debate about whether Roan and Ticking in dogs are truly separate, or just variations on the same gene. I am not aware of any papers yet published with molecular studies, but it does seem that roan dogs, when outcrossed to non-roan breeds, end up with offspring that look a lot like the Belton setters. Certainly whether these are separate, similar genes or the same gene with layers of modifiers, the end result is that dogs have independent factors that will “recolor” the area that a piebald gene left white.

It didn’t seem that horses had that, at least not until recently.

In 2009 a French sport horse, Vision Morinda was foaled.

Clicking on the image above will take you to the website for her breeder, and her page which has many high-quality photos of her at all ages.

At first glance, it is tempting to assume that Vision Morinda is a tobiano with very loud cat tracking. The problem is that she cannot be homozygous. Her dam is brown. (Note that the mare she is pictured with is a surrogate. Her dam, Scarlett Fontanel, is pictured here.) But perhaps even more intriguing is the fact that her spotting seems to have intensified as she matured. That’s something that is typical of the Belton patterns. As most people are aware thanks to the Disney movie, Dalmatian puppies are born white and develop their spots later. That’s true of the English Setters and the Australian Cattle Dogs. Here is my friend Mary’s (extremely cute) Cattle Dog mix, Volt, as a puppy. (Thank you, Mary, for letting me share your photos!)

As you can see, he looks like a white dog with black patches. He is an extreme piebald. That’s why he has white ears. Well, mostly white ears. He was already starting to show some spotting there. His back and sides, however, looked white. But here is Volt today, as a grown dog.

As you can see, he developed his ticking – the Belton-type pattern – over time.

In a less dramatic fashion, Vision Morinda seems to have spotting that intensified as she matured. (Her breeders even comment on her page about the surprise of getting an English Setter color on their horse.) The spotting on her is also different, visually, from a typical tobiano with cat tracks. The pattern is evenly distributed. The spacing does change somewhat (notably across her shoulder) but it still is pretty consistent across the white areas, rather than clustering into spots or patches. It looks like the ticking you would see on a dog, not a horse.

This raises the question of whether there is some factor in horses that can add ticking – a Belton pattern, so to speak. I have a few more horses to share, all with odd spotting patterns. None are quite like Vision, but all have unexplained dark spots inside white patterns or markings. They all come from my “weird stuff” files. That’s where I put things that don’t make sense, or just seem “off” in some fashion. Sometimes enough of them accumulate – like the odd late greys from a few months ago – that it seems like there might be some thread connecting them all. I am not sure these horses really have a common thread, because they do have some visual differences, but I’m going to start posting them just to see if more turn up. That’s what happened with those greys (I have more that I need to post in the future, by the way!) so maybe sharing them will bring others out of the woodwork!

(Images at the top of the post are courtesy of Wikipedia. Images of historical English Setters come from The Pointer and Setter in America, published in 1911, and Country Life, Volume 22, 1907.)

Images of leopard appaloosas with Dalmatian dogs are always eye-catching. Certainly they can look quite closely matched, like this Polish Malopolski and his buddy. Even so, the patterns in the two species are very different in terms of what is really happening to the pigment on the animal. That’s probably off in the weeds for most owners and breeders, but for artists the distinction is actually pretty important.

This touches on one of the reasons why artists who develop an interest in horse color often have such a different perspective. Usually the kind of information a breeder needs is predictive. That is, they need to know what might likely result from crossing this to that, or what they might need to cross if this particular end result is what was wanted. What artists need to know isn’t about prediction nearly so much as it is about possibilities. Not so much what might happen, but what could happen – even far-out-there, not-very-likely, could happen. That’s because artists often want to add something for interest or for composition. For those producing realistic art, that has to be done within the constraints of what is possible. It doesn’t necessarily have to be likely, but it does have to be possible. This unique perspective became apparent to me a number of years ago when I gave my first presentation on horse color. In the question and answer period afterwards, someone in the audience asked if a horse could be both dappled and fleabitten at the same time. It was clear that was not the sort of question my fellow presenter, Dr. Sponenberg, often heard. But it is precisely the kind of question that equine artists ask all the time. Scientists might not notice this kind of detail on an individual horse, but for someone who paints horses, this kind of information – does this happen with this? – has a lot of practical value.

So why do artists need to understand the process behind appaloosa patterns? Spotting is a useful tool, because it breaks up positive and negative space. It makes the horse more visually interesting. If you are particularly clever, it can be used to draw the eye in a way that works with the composition, or to hide flaws. But spotting doesn’t just happen anywhere. It follows rules, and those rules depend with what is happening with the pigment. Understanding the underlying mechanism makes it far less likely that you’ll add some interesting detail that isn’t realistic. When dealing with rare combinations of colors and patterns, it might be difficult to find a reference image to consult. Knowing the process can tell you if there is a reason to bother looking in the first place, because it tells you what is possible. (And when you wing it without a reference, the knowledge will make for more reliable guesses.)

“Trouble”, sculpted by Sarah Minkiewicz-Breunig and glazed by Lesli Kathman.
In the collection of Melissa Gaulding.

This is a ceramic collectible with the kind of spotting (often called cat tracking) seen in homozygous tobianos. It’s a really popular effect. In my normal job (the one I have when I am not trying to get a horse color book to press), I have produced quite a number of these. The problem comes when this gets confused with leopard spotting, and most especially what happens when leopard patterns are combined with the tobiano pattern. That brings us back to the image at the beginning of the post. These three images – the leopard, the Dalmatian, and my ceramic foal –  represent three very different scenarios in terms of the underlying process. I want to take each, one at a time, and explain how they are different despite looking so similar.

This is the typical nose-to-toes kind of leopard. Most people would think of this as a white horse with black spots that have been superimposed on top. That’s not really accurate. From a genetic standpoint, this kind of horse is a two-step process. First she has inherited a gene that progressively adds white hairs to the coat. Those hairs, over time, are going to produce the fairly distinctive pattern known as varnish roan. If the pony in my illustration just had that first gene, she would look like a black version of this pony.

That first gene, known as Leopard Complex, sets things up for leopard but it doesn’t make leopard patterns itself.

That happens when the horse inherits a separate patterning gene in addition to Leopard Complex. In this case, that patterning gene is called Pattern1. What Pattern1 does is take the white from Leopard Complex and amplifies and organizes it. So while our horse looks like she is white with spots, it is perhaps more helpful to think of her as a horse that was roan, but Pattern1 has now taken that mixture of white and dark hair  and reorganized it. Underneath the white hair, what that horse may look like is closer to this.

This is what the underlying skin looks like. She probably does have some truly white skin in the area where a blanket pattern would go. Pattern1 does amplify the white, after all. But under it all she isn’t really a white horse, at least not in the sense that most people would think of as true white. She is more like a roan horse that has been modified a bit. That’s why even nose-to-toes leopards have faces that are shaded much more like a grey than a cremello, because for the most part the face has dark skin, not pink skin. And that is why a pintaloosa looks like this:

The true white areas of the tobiano pattern cover over the appaloosa pattern. The spots from the leopard pattern don’t spread over onto the tobiano pattern because the process with Pattern1 isn’t “add dark spots to the white”, it is “organize the roan into spots.” So the spots don’t happen where the tobiano pattern already took all the roan away. Without the color there in the first place, Pattern1 has nothing to work with.

Of course, if we moved our tobiano pattern out a bit, encompassing more of the dark skin and butting it up close to the “blanket” skin, we could probably get something that looked a bit like the leopard spots migrated over some of the tobiano.

Even so, the spotting is still concentrated in such a way that shows it is an appaloosa pattern with a tobiano pattern layered over the top of it. The spots on the flanks might look like they are in the tobiano white, but really they are just in an area that was already white from the action of the Pattern1 gene. The action is still the same. The tobiano is there adding true, pink-skinned white on the horse, and underneath it Leopard Complex and Pattern1 are just doing their thing.

Even with the tobiano bumping up to the pink-skinned areas of the leopard pattern, it still looks different from the kind of spotting that comes from a horse having two copies of the tobiano gene.

This is a (presumably) homozygous tobiano with cat tracks. Whereas Leopard Complex is a roaning process that Pattern1 takes and organizes into the leopard pattern, this type of spotting is more like a not-entirely-successful attempt to add some more color to a horse that already has large patches of color. Unlike the existing spots, which are large and opaque, these new spots are small and vary in opacity. Some just come through in specks.

Cat tracking tends to cluster around the existing spots to some extent, almost as if these new spots want to occupy the same general area as the existing spots. This is quite different from the spotting on a leopard, which tends to be dispersed across the body.

The exception is the hooves. Tobianos with cat tracks often have a concentration of spots around the coronary band, often turning the hoof completely dark or nearly so.

There are spots on the legs, but typically they are not as numerous as the ones around the feet. The same is true for the face. This is the face that goes with these feet. He does have a few spots in his blaze, but they are not extensive.

So how is this different from the Dalmatian? Well he really is a white animal with colored spots added on top. In dogs, the gene for this is usually called Ticking, but since ticking means something different in horses, I am going to use the older English term for the pattern, which is belton. This post has run really long, so I’ll split that over into a second part. And why delve into the belton pattern in dogs? Because lately there has been a handful of horses that have turned up that just might have that kind of spotting. At the very least there are horses with dark spots inside their white markings that are not tobiano cat tracking and not leopard patterning. More on those will appear in the next post!