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
A gastric-ulcer condition of swine was first recognized as a definite disease entity at the Boar Testing Station at Ames, Iowa in early 1957 in pigs that had been farrowed in the fall of 1956. The condition was at first thought to be bloody dysentery, but the feces were not typical in that no apparent break of free blood occurred. Since the condition has been recognized as a separate entity, cases have been reported from the field.
Berg, John N.
"A Gastric-Ulcer Condition of Swine,"
Iowa State University Veterinarian: Vol. 22
, Article 2.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol22/iss2/2