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 October 22, 1946, a 4-year-old male German Shepherd was admitted to the Stange Memorial Clinic. The owner's history of the case included vomiting and failure to eat for 3 days. The owner was reasonably sure that the dog had not passed urine for several days. The bladder had been emptied by the local veterinarian through the use of a trocar and canula on the morning of the day that the case was admitted.
Stellinger, C. J.
"Uremia Due to Cystic Prostate in the Dog,"
Iowa State University Veterinarian: Vol. 9
, Article 14.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol9/iss1/14