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
Among the many other war shortages, absorbable sutures are becoming very scarce and the supply of raw material for producing them is difficult to obtain. This is because the so-called "cat gut" suture material is obtained from the upper 8 or 9 feet of the small intestine of sheep.
Stouder, K. W.
"Sheep Nodule Worms,"
Iowa State University Veterinarian: Vol. 5
, Article 6.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol5/iss2/6