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
Field practitioners are frequently confronted with the problem of diagnosis of disease of pregnant ewes that show weakness, depression, anorexia and a variety of central nervous disturbances as incoordination, circling, convulsions or coma. The frequent diagnosis of pregnancy disease in these cases may be misleading as to the prevalence of this condition. This syndrome may be confused with listeriosis, brain abscesses, enterotoxemia, hemorrhagic septicemia, plant and chemical poisons and rickettsial conjunctivitis.
Lebeck, Alvin D. and Cheville, Norman
"Diagnosis of Pregnancy Disease in Sheep,"
Iowa State University Veterinarian: Vol. 21
, Article 6.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol21/iss1/6