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 Oct. 17, 1957, a 2-year old gelding of mixed breeding was entered at the Stange Memorial Veterinary Clinic to have a tumor removed from his right foreleg. The tumor was found to be about 11/2 inches in diameter, ulcerated, and attached to the skin and subcutaneous tissue, allowing it to be freely moveable.
Berthelsen, John D.
"Equine "Blood Wart","
Iowa State University Veterinarian: Vol. 20
, Article 7.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol20/iss1/7