Color Question (Never seen spots like these.)

[ecileh]

I am leasing a youngster as a project while my mare heals from an injury and have never seen spots like the ones on Sawyer’s butt before.

https://goo.gl/photos/pF7bQzi6UCwfT3EU6

They are not a lighter shade of bay. They are bay with white hair mixed in/over-laid. He is, of course, in winter coat right now, so perhaps they will look different in the spring?

I am told he is a paint/draft cross–though I do not know what the draft is. Anyway. I know next to nothing about paints–is this actually a common marking?

Just curious.

[SendenHorse]

white hairs tend to be longer than dark hair in the winter so it could be that-- but I have seen that color on non-winter horses too…

[Bluey]

Here it is, directly from the horse’s mouth, so to say:

http://press.apha.com/pdfs/guidebooks/ColorGenGuide.pdf

Read the last paragraph on the first example, tobiano.

—“Other details of the tobiano pattern include the fact that on many of these horses, the border between the white and colored areas consists of pigmented skin overlaid by white hairs. The result is usually a bluish cast to
Tobiano
Typical Tobiano Patterns
the border, almost like a halo or a shadow. Another peculiarity of some tobianos is the presence of “ink spots” in the white patch- es. These spots are small and generally round in shape.”—

[ecileh]

Thanks, Bluey!

He has a few of the ink spots on his face and lower legs, too!

[Scribbler]

I have read that the ink spots occur on horses that are homozygous for the tobiano gene, but this horse does not look homozygous, because the colour continues over his back.

I think it’s possible he also has the frame overo gene, and is expressing some of those lacy overo spots on the parts of him that are white from the tobiano gene. The frame overo gene would also account for the colour that crosses the back.

Here is a nicely-marked frame overo:

http://southshadow.homestead.com/APHA_Stallion.html

[scheherazadetbmare]

I love it!
Never question pintos. They are all great and some, like yours, are unique.
My pinto has faded out to “white,” except for one spot on his rump. His skin still has the “right pinto color” but except for his one dark spot on top of his rump, he is called “white” by many people.
Enjoy color. I’ve had pintos all my life. Love them.

[Bluey]

Our paint, he too had some of that roany spotted pattern, he was 28 here.
He was an awesome horse for us for 20 years:

[ecileh]

I have always been a sucker for any animal with interesting/strange markings–I think they add character.

[Scribbler]

Pinto patterns are very interesting. If the horse has just one pattern gene (ie, just tobiano, just overo, just splash), the patterns will be fairly predictable but the level of expression (the percent of colour to white) will not be. So if you have a tobiano with “maximum colour/minimum white” expression, the pattern will be similar (but never identical) to a tobiano with the same level of expression. And if you have a tobiano with 50/50 colour/white expression, the pattern will be recognizably the same as other tobianos with the same expression.

If the horse has genes for different patterns, such as tobiano + overo, or tobiano + splash, the patterns tend to get much wilder and more random. I think it is also more likely that you will get a white horse with blue eyes, or a “medicine hat” horse, which is white with pink skin, and only a spot of colour on the top of the head and ears.

http://www.cameopaints.net/horse-photo.php?id=13

A horse can carry a pinto gene with minimum expression, for instance an Overo with no pinto spots, just high socks and a big blaze. So before genetic testing, we didn’t really know necessarily the genetics behind various patterns.

BTW, Overo pattern apparently mutated in the Americas. There may be imported Overos in Europe now, but not historically. That is why the British don’t have a word to distinguish between Tobiano and Overo patterns. They call a black pinto a piebald, and other colours skewbald, but they are all Tobiano patterns.

[ecileh]

That is why the British don’t have a word to distinguish between Tobiano and Overo patterns. They call a black pinto a piebald, and other colours skewbald, but they are all Tobiano patterns.

Interesting! I always thought the piebald vs skewbald thing had to do with how much white a horse had on its face, not with the other color.