The
tail of the horse and other equines consists of two parts, the
dock and the skirt. The dock consists of the muscles and skin covering the
coccygeal vertebrae. The term "skirt" refers to the long hairs that fall below the dock. On a horse, long, thick tail hairs begin to grow at the base of the tail, and grow along the top and sides of the dock. In
donkeys and other members of
Equus asinus, as well as some
mules, the
zebra and the wild
Przewalski's horse, the dock has short hair at the top of the dock, with longer, coarser skirt hairs beginning to grow only toward the bottom of the dock. Hair does not grow at all on the underside of the dock.