LEUCINE UROLITHIASIS IN A 3 WEEKS OLD MIXED GERMAN SHEPHERD PUPPY.

Canine urolithiasis is a common disorder of the urinary tract, characterized by stones located anywhere within the urinary tract, which is mostly encountered in middle-aged to older dogs. Urolithiasis is influenced by familial, congenital and pathophysiological factors including urinary pH, dehydration, urinary infection, anatomical abnormalities and drug administration. A 3 weeks old mixed German Shepherd male puppy with no antecedent clinical signs (sudden death) was submitted to the Pathology Department for necropsy. The animal was suspected of bronchopneumonia ab ingestis due to milk aspiration. Necropsy, cytological and histological exams were performed. Grossly, a large amount of urine was found within the peritoneal cavity (uroperitoneum) secondary to urinary bladder rupture, severe bilateral hydronephrosis and hydroureter, and urethral obstruction with numerous large white to gray calculi varying in size from 2-10mm were identified. The cytological exam showed several large, white to yellow spheroids with radial concentric laminations consistent with leucine crystals. Histologically, the renal tubules were diffusely dilated and contained pale eosinophilic hyaline casts, sloughed necrotic epithelial cells and lamellated concretions of amphophilic radiating structures. A diagnosis of urethral obstruction due to leucine urolithiasis was made, and it was associated with hydronephrosis, hydroureter and urinary bladder rupture. To the best of the authors' knowledge this is the first report of leucine urolithiasis in a dog in Romania. [ABSTRACT FROM AUTHOR]