Originally Posted by bubba13
All base color rules apply regardless of pattern.
Horses can be homozyous black without two black parents, but they have to both be black-based (bay, perlino, dun, buckskin, etc.). Your mare, with a chestnut parent, would have to be heterozygous black, as chestnut horses are homozygous red by definition and do not carry a black gene to pass on.
So without a genetic test it's certain my mare is heterozygous black? Thanks