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
Hernia is the protrusion of an organ, or part of an organ or other structure, through the wall of the cavity normally containing it. While the term applies to other regions of the body, in farm animals it refers to defects in the abdominal wall, unless otherwise qualified, and is the protrusion of a viscus, or viscera, through a natural or abnormal opening in the abdominal wall over which the skin remains intact. Rupture is its every-day synonym, and perhaps is a more widely used term than the more correct hernia.
Carman, Grant M.
"Hernia and Its Heredity,"
Iowa State University Veterinarian: Vol. 14
, Article 3.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol14/iss3/3