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
On LI Dec. 26, 1940, Dr. M. S. Campbell, Brookfield, Mo., was called to investigate the death loss in a flock of 800 feeder lambs. These lambs had been on feed for sometime and until the time of the call had been doing well. It seemed that the animals affected were the largest and fattest of the flock.
Campbell, R. L.
"Entero-intoxication in Sheep,"
Iowa State University Veterinarian: Vol. 3
, Article 11.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol3/iss3/11