OOOOOOOH Check this guy out!

Normally I would say it's a "gold spot", but it's size and shape makes me wonder about chimera.

A gold spot is something like this (which was also more contrasted in person):
[img]http://www.accphotography.com/gallery/d…]

it's bizzare especially the way it borders the white on the shoulder going down to the right leg - I think you are right maybe this is Chimera.

He does have that two-horses-welded-together look of a chimera, reminds me of a tortoiseshell and white cat I saw once with a big blue patch on the shoulder that overlay the yellow, black and white underneath.

I was thinking Chimera too.

The way it borders the white was just weird. And the mane is actually more sorrel/chestnut than anything.

ETA: ACC could you explain what a gold spot is?

Nope, I can't. I'm not sure anyone can. I've never even heard any theories.

That's cool! And I like his pinto markings, too! :)

Chimeras are rare and not generally detectable. I would think a true chimera would follow the migration patterns of the cells, if it were being expressed in the coat, since the fusion of the zygote happens at such an early stage of development. This is more likely a random event, where a biochemical misfire produced a pigment switch, or somesuch, or mosaicism.

I think it's really hard to tell just how common it is when it's not always visible and even when it is some people don't recognize it. The only way to know with this one would be to test, but I think it more likely it's somatic with this horse.

wow how unusual

Very cool coloring.

So, do you think a gold spot is the 'gold ' equivelant of a blood spot?

I am familiar with Chimera but not with somatic or mosaicism?

Probably.

Mosaicism is the same thing as chimerism. Somatic mutation: http://ghr.nlm.nih.gov/glossary=somatic…" onclick="window.open(this.href);return false;