This week will be a bit of a catch-all, covering a variety of patterns of white hairs that are neither grey, classic roan, face and leg markings, or associated with white spotting. (Varnish roan, for instance, is a leopard gene pattern, and sabino and dominant white may also produce roaning as part of the pattern.) The genetics of none are well understood. Following Sponenberg, I will list and describe them here. Sorry for the lack of photos, but I haven’t even seen all of these patterns myself.

The first, frosty, may be a variant of classic roan, as it is found in the same breeds. In this pattern, the roaning is most pronounced over bony areas such as the hips, and roaning may affect the mane, tail and head as well as the body. “Squaw manes” and “squaw tails” with white hair mixed in often indicate the frosty pattern…