Iowa State University Veterinarian Records, RS 22/6/0/9, University Archives, Special Collections Department, Iowa State University, http://www.add.lib.iastate.edu/spcl/arch/rgrp/22-6-0-9.html
This operation is a form of cosmetic surgery confined by fashion almost exclusively to the show horse. The object of the operation is to remove the function of the depressor muscles of the tail thereby enabling the horse to carry its tail higher than normal. The higher carriage of the tail adds much to the beauty of the animal in the show ring and on the bridle paths.
Whitcomb, Oliver W.
"Subcutaneous Caudal Myotomy,"
Iowa State University Veterinarian: Vol. 13
, Article 4.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol13/iss2/4