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
Diseases of the myocardium can be classified either as primary or secondary. Primary cardiomyopathies include idiopathic congestive or hypertropic forms. Causes of secondary cardiomyopathies are primary, systemic diseases, the most common of which are infectious, metabolic, toxic, ischemic, and neoplastic diseases that cause some myocardial damage.
Rojohn, Claire E. II and Hill, Brian L.
"Congestive Cardiomyopathy in the Canine,"
Iowa State University Veterinarian: Vol. 46
, Article 6.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol46/iss2/6