Brindle is a mismark in labs, but I've heard of it happening before.
http://www.woodhavenlabs.com/mismarks.html
I do know that brindle in shelties is highly debatable as brindle is a dominant gene so many people believe they're crossbred.
http://www.woodhavenlabs.com/mismarks.html
I do know that brindle in shelties is highly debatable as brindle is a dominant gene so many people believe they're crossbred.