Trabag - Manchado Chestnut Arabian

Going though old photo's and thought I'd get a few opinions from the colour guru's.

This is a purebred Arabian mare, foaled 1946. She never passed this colour onto any of her foals.
So far it's only appeared in horses from Argentina. So it's an enviromental affected colour?

Pedigree?
Im asking because there was a big German breeder who relocated to Argentina in the 60's, I believe......although unlikely of his lines...they were mainly dark bay and black, an occasional chestnut, with nearly zero chrome.....

This is all I could find:

Trabag Arabian

I know she was owned by Lady Wentworth and was shown and won Championships.
Still doing some more digging, so I'll post what I find out. :)

Wow! That is very interesting. I can't wait to see what you dig up on her.

She is super cool looking, kind of has the same pattern as a pintaloosa.

She lived earlier than "my" German emigrants.
Truly interesting, tho. There's gotta be a full pedigree somewhere of her.
Now I wish Mr. Chairman of the German association would read this...for him any Arabian with any pinto marking can't be purebred......

Yes environmental factor I'd say. Probably fungal :/
But she's cool!

White markings and fungal infections « The Equine Tapestry

It's highly likely to be an environmental factor since it is only in horses living in Argentina (Arabians, Thoroughbreds, etc.) so it technically isn't a pinto pattern as it wouldn't be hereditary if it was environmental. I would call it an environmentally-induced pinto mimic XD

Gotta say, though, it's a gorgeous thing to look at.

I don't know. I think I am in the "recessive gene" camp. If it's environmental, why do we not see more of it? For that matter, if it's environmental, is it something mares are exposed to during gestation? I can't find any pictures of a foal displaying the pattern, but if it were something that was a drastic change of coat like a fungal infection could cause, why are there no reports of that part of it?