This just in.
Most horses are born capable of shifting between a walk, trot, canter, and gallop on their own. In a few extremely rare cases however horses are born without this ability. “Effectively it’s like a car that can’t shift gears” said Dr. Alan K. Haulic, a leading scientist working on the disorder.
It seems to be linked to the gene that determines hair color, as all known cases are pure white in color. They are however not albino, nor are all white horses effected. They tend to be shunned by other horses and as such are only ever found in remote areas.
Given time however as these horses mature they will develop the ability to “change gears” on their own. In all cases studied so far this has developed at the same time as the growth of a single spiral horn in the center of the forehead.
This has led Dr. Haulic’s team to theorise that it is not a horn at all.
It’s simply a horse with a stick shift.