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 lesions of chronic interstitial nephritis are commonly found in dogs over eight years of age. however, the clinical significance is of little importance in a majority of these cases, The specific etiologic agent is not easily defined and history of the individual case must be considered. Possible causes include: 1) past renal injury from Leptospira, 2) ingested nephrotoxic materials with resultant kidney scarring, or 3) chronic renal infections from bacteria, viruses, or parasites.
Armbrecht, Paul J. and Baker, George
"Chronic Interstitial Nephritis in the Dog,"
Iowa State University Veterinarian: Vol. 33
, Article 12.
Available at: http://lib.dr.iastate.edu/iowastate_veterinarian/vol33/iss3/12