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
In considering the field of sheep diseases we can roughly divide them into three general groups: (1) infectious, (2) non-infectious, and (3) parasitic. In Iowa most of our conditions are concerned with problems of parasitism and/or nutrition. For the most part they will be found not too difficult to diagnose and amenable to therapy.
Beardmore, H. F.
Iowa State University Veterinarian: Vol. 6
, Article 4.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol6/iss4/4