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
The total and differential leukocyte counts are the tests used in monitoring the leukocyte numbers and proportions in large vessel peripheral blood. Knowledge of leukocyte origin, function, and transitory presence in the peripheral blood is imperative when evaluating change in white blood cell and differential counts.
Den Herder, Jerry and Prasse, K. W.
"Leukocyte Response in the Dog and Cat,"
Iowa State University Veterinarian: Vol. 34
, Article 3.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol34/iss2/3