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 5-year old spayed female Cocker Spaniel was admitted with a sudden onset of dyspnea, cyanosis, depression, elevated heart rate, and dilated pupils. The dog encountered no trauma prior to the onset of clinical signs and had no access to poisons. The dog was normally active.
Novotny, Mark J.
"What's Your Radiographic Diagnosis?,"
Iowa State University Veterinarian: Vol. 41
, Article 10.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol41/iss3/10