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
It has often been stated that the most important single test in a urinalysis is the determination of specific gravity. No other test gives as much information regarding kidney function in dogs as quickly while utilizing so little time and equipment, requiring only a urinometer. Veterinarians should purchase the infant size instrument since the quantity of urine obtained is often too small to float a large urinometer. It is wise to check any new instrument for accuracy using distilled water as a standard or some other liquid of known specific gravity.
Zontine, W. J.
"Urine Specific Gravity,"
Iowa State University Veterinarian: Vol. 22
, Article 2.
Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol22/iss1/2