Weaving. Movement like a Bear in a Cage.
This consists in a lateral rocking of the head and neck, and sometimes of the chest as well with alternate stepping on the right and left fore feet. It has been supposed to represent the movement of the weaver in working a hand loom, or still better the movement of a caged wild beast in constant turning toward the right and left of the front of his cage. The motions are as regular as a pendulum, and involve the contraction of corresponding groups of muscles on the two sides of the body.
They seem, in some cases, to begin in impatience in waiting for the feed, while other horses in the same row are being attended to first, but when the habit has been formed it may be continued most of the time in the intervals between feeds as well. Nervous horses and those that are hearty feeders are the most subject to this infirmity.