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 Sept. 9, 1950, a Spitz dog was admitted to Stange Memorial Clinic. It had the history of being unable to urinate. Further history was that these attacks had been coming on for some time and that during this last one the dog had not urinated for two days. Urethral calculi were suspected.
Perkins, D. H.
"Cystic Calculi in a Spitz,"
Iowa State University Veterinarian: Vol. 13
, Article 12.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol13/iss1/12