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
During the first week in April. 1941 a veterinarian at Hull, Iowa was called by one of his clients to see some sick horses. The condition was diagnosed as strangles and treated accordingly.
"Purpura Hemorrhagica In Man,"
Iowa State University Veterinarian: Vol. 4
, Article 11.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol4/iss3/11