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
A mixed Collie, one-year-old, was admitted to the Stange Memorial Clinic on July 12, 1951. Early diagnosis supposed a broken jaw. The dog was placed on the operating table in left 39 lateral recumbency. Sixteen gr. of Sodium Pentabarbital were given intravenously. The mandible was examined and a fracture of the symphysis was found.
Freeman, E. M.
"Separation of the Symphysis Mandibulae,"
Iowa State University Veterinarian: Vol. 14
, Article 14.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol14/iss1/14