December 2011

1211
Text

 

History: Dog, Labrador retriever, 8 years, male.

Diagnosis: Urinary bladder: urocystitis, mild, diffuse, chronic with urate calculi

Description: The urinary bladder was distended by approximately 400 ml dark brown to greenish urine. The dark green calculi measured up to 0.3 cm in diameter and were consistent with urate containing crystals.

Comments: Necropsy revealed a severe, intrahepatic icterus due to end stage hepatopathy of unknown cause. The cortex of both kidneys was diffusely pale green discoloured. Histologically, pigment casts containing bile were multifocally evident in the proximal tubules. Additionally, multifocal distal tubules were severely dilated due to obstruction by bile pigment. Multifocal hemosiderosis was present in the liver, spleen, kidneys and mesenteric lymphnodes, likely as a result of hepatic failure.

Urate calculi are common in dogs. They arise from an increased renal excretion of urates. Both a genetic in male Dalmatians, as well as chronic hepatic failure may lead to defective hepatocellular uptake of uric acid. In addition, urate containing calculi may be deposited in kidneys and the urinary bladder in dogs with a portosystemic shunt.

Picture by: Kristina Dietert, Department of Veterinary Pathology, Freie Universitaet Berlin, Germany

Author: Marie-Charlotte von Deetzen, Department of Veterinary Pathology, Freie Universitaet Berlin, Germany