January 2018
U-M12 (NP)

Signalment (JPC #82-2228):  Angora Goat

HISTORY:  Tissue from an Angora goat.  On examination the kidneys appeared uniformly brown.  Upon transection, the discoloration was found to be limited to the cortices of both kidneys

HISTOPATHOLOGIC DESCRIPTION:  Kidney:  Approximately 40% of the proximal convoluted tubules within the renal cortex have thickened, 8-12 micron wide, reddish brown to black pigmented basement membranes.  Rarely, tubules contain granular basophilic material (mineral).

MORPHOLOGIC DIAGNOSIS:  Kidney, cortex, proximal convoluted tubules, basement membrane:  Pigmentation, multifocal, moderate, Angora, caprine.

CONDITION:  Cloisonné kidney

CAUSE:  Unknown



TYPICAL GROSS FINDINGS:  Uniform brown-black discoloration throughout the renal cortex, stopping abruptly at the corticomedullary junction 

TYPICAL LIGHT MICROSCOPIC FINDINGS:  Curving, wire-like dark brown to gray/brown pigmented thickening of the basement membranes of proximal convoluted tubules


Gross:  renal hemosiderosis, post-mortem discoloration, hemoglobinuric nephrosis (gunmetal blue kidney)

The gross appearance, with the discoloration affecting only the cortex and stopping abruptly at the cortico medullary junction differentiates from all other entities

COMPARATIVE PATHOLOGY:  Described only in the goat


  1. Cianciolo RE, Mohr FC. Urinary system. In: Maxie MG, ed. Jubb, Kennedy, and Palmer’s Pathology of Domestic Animals. 6th ed. St. Louis, MO: Elsevier; 2016:429.
  2. Jones TC, Hunt RD, King NW. Urinary system. In: Veterinary Pathology. 6th ed. Baltimore, MD: Williams and Wilkins; 1997:1131-1132.
  3. Breshears MA, Confer AW. The urinary system. In: McGavin MD, Zachary JF, ed. Pathologic Basis of Veterinary Disease. 6th ed. St. Louis, MO: Elsevier Mosby; 2016:628.


Cudd 2017



Click the slide to view.

Click on image for diagnostic series.

Back | Home | Contact Us | Links | Help |