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
Reports of neoplasms of canine urinary bladder are not uncommon in the literature, however, this condition is not frequently seen in practice. The urinary bladder mucosa is most frequently involved with single or multiple, papillomas or carcinomas. Mesenchymal tumors occur less frequently and usually involve the smooth muscle (leiomyomas).
Judge, Francis J.
"Papilloma of the Canine Urinary Bladder,"
Iowa State University Veterinarian: Vol. 22
, Article 9.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol22/iss3/9