Frame overo


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!

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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.)