January 2018
U-M16 (NP)

SIGNALMENT (Accession #: 1951287):  10-year-old Suffolk ram

HISTORY:  A 10-year-old Suffolk ram died after a two-day illness.  At necropsy, both kidneys were swollen and had roughened surfaces.

HISTOPATHOLOGIC DESCRIPTION:  (Slide A)  Kidney:  Diffusely affecting 100% of this section there is extensive glomerular loss, with the remaining glomeruli exhibiting one or more of the following changes: expansion of the glomerulus up to three times normal by an increase in mesangium characterized by abundant eosinophilic homogenous to fibrillar material; increased mesangial cellularity; vacuolation of the mesangium; hypersegmented glomerular tufts; parietal and visceral epithelial hyperplasia and hypertrophy; adhesions between glomerular tufts and Bowman’s capsule (synechiae); sclerosis or obsolescence of the glomerulus; thickening of Bowman’s capsule; and periglomerular fibrosis. In the cortex and medulla, there is extensive tubule loss, and remaining tubules exhibit one or more of the following changes: ectasia with an attenuated epithelium lining, filling of lumina with proteinaceous or cellular casts and rarely small amounts of mineral; degeneration with swollen vacuolated epithelial cells; necrosis with shrunken hypereosinophilic epithelium which are often sloughed; and regeneration with increased cytoplasmic basophilia, piling up of cells, and rare mitotic figures.  Multifocally infiltrating the cortical and medullary interstitium are numerous lymphocytes, plasma cells, and fewer macrophages, admixed with variably dense and abundant fibrous connective tissue that separates and surrounds remaining tubules and glomeruli.  Diffusely the capsule is thickened up to 60 microns by fibrosis.

(Slide B)  Kidney (Periodic Acid Methenamine Silver, PAMS):  Basement membranes of Bowman’s capsule and tubules are diffusely thickened up to 2-3 times normal.  Frequently, glomerular capillary basement membranes are also thickened and densely packed. 

MORPHOLOGIC DIAGNOSIS:  Kidney:  Glomerulonephritis, membranoproliferative, diffuse, severe with synechiae, tubular degeneration, necrosis, regeneration, and loss, protein and cellular casts, and multifocal chronic lymphoplasmacytic interstitial nephritis, Suffolk, ovine.

ETIOLOGIC DIAGNOSIS:  Idiopathic glomerulonephritis

CAUSE:  Etiologies may include idiopathic, viral, bacterial, parasitic or neoplastic conditions










  1. Breshears MA, Confer AW. The urinary system In: Zachary JF ed. Pathologic Basis of Veterinary Disease, 6th ed., St. Louis, MO: Elsevier, 2017:644-649.
  2. Cianciolo RE, et al. World small animal veterinary association renal pathology initiative: Classification of glomerular diseases in dogs. Vet Pathol. 2016;53(1):113-135.
  3. Cianciolo RE, Mohr FC.: Urinary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. Vol. 2, 6th ed. St. Louis, MO: Elsevier; 2016:401-413.
  4. Cline JM, Brignolo L, Ford EW. Urogenital system. In: Abee CR, Mansfield K, Tardiff S, Morris T, eds. Nonhuman Primates in Biomedical Research: Disease. Vol. 2. London, UK: Academic Press, 2012:489-491.
  5. Murray GM, Sharpe AE. Nephrotic syndrome due to glomerulopathy in an Irish dairy cow. Vet Rec. 2009;164(6):179-80.
  6. Slauson DO, Cooper BJ. Mechanisms of Disease, 3rd ed. St. Louis, MO: Mosby, 2002:274-281.
  7. Vezzali E, Manno RA, Salerno D, Oberto G, Nyska A, Ramot Y. Spontaneous glomerulonephritis in Göttingen minipigs. Toxicol Pathol. 2011;39(4):700-5.
  8. Wilson FD, Wills RW, Senties-Cue CG, Maslin WR, Stayer PA, Magee DL. High incidence of glomerulonephritis associated with inclusion body hepatitis in broiler chickens: routine histopathology and histomorphometric studies. Avian Dis. 2010;54(3):975-80.


Click the slide to view.

Click on image for diagnostic series.

Back | Home | Contact Us | Links | Help |