Japanese images of horse had always left me with some unresolved questions. Why were there paintings of horses apparently hoisted up in their stables? And what purpose exactly was served by those long cloths wrapped around their bellies?
The first observation also troubled the missionary Luis Frois, who drafted his observations and comparisons of Japanese and European life, written in 1585:
In the stables of our nobles, the horses often lie down; those in Japan, day or night, are nearly always kept standing by a belt tied round the belly.
Clearly it seemed cruel not to allow the animals to lie down, but the editors of The First European Description of Japan 1585 (cf. footnote 1) clarify the practice: Horses do not usually sleep for extended periods like humans. They instead take frequent short naps of several minutes duration. Adult horses mostly sleep standing up, with the front legs and one hind leg doing most of the weight bearing (the horses shift their weight and have keg bones with “stay apparatus” that allows they muscles to relax without collapsing. 
Another curiosity seen in netsuke is the image of a horse with its stomach bound with a broad cloth and tied at its back. An interesting article appeared in vol. 48 of Daruma magazine, discussing Japanese horse trappings. The author, Lisa R. Ryan, describes three types of cloth uma gake (horse coverings): hara gake (stomach coverings), shiri gake (rump or buttock coverings) and yui age – literally ‘tied up’.
Dating from the Edo period, the author believes they were originally used by travelling daimyo to display their crests and then as colourful adornment during festival celebrations, before later being adopted by merchants and the like.
The votive tablets, or ema, found at Shinto shrines often show horses with their bellies wrapped in the long yui age.
Ema from Sakurayama Hachimangu, Takayama
Horses are regarded as the steed of the gods and as such were offered up when asking for a special blessing. Live animals were replaced with clay models and painted tablets such as the one illustrated here. (White horses are still kept at the sacred stable at Nikko, a carved transom with three wise monkeys protecting them from harm). The elaborately wrapped stomach of the animal indicates that it is offered as a gift in the Japanese tradition of beautiful wrapping (tsutsumu).
- Danford, Richard K. Gill, Robin D. and Reff, Daniel T., The first European description of Japan, 1585. A critical English-language edition of Striking Contrasts in the Customs of Europe and Japan by Luis Frois, S.J., 2014, p. 129
- Literally ‘horse painting’, though other subjects may be illustrated