In a 15 month old Siberian husky, radiography and ultrasono-graphy demonstrated a distorted left kidney with severe pyelectasia (over 8 cm) and a distended ureter (1·9 cm) filled with echogenic fluid and no obstructive lesions. The dog was diagnosed with primary pyonephrosis accompanied by suppurative pyelonephritis and ureteritis causing fibrosis in the left ureter histopathologically.
Primary pyonephrosis uncommonly develops when pyelonephritis is followed by subsequent obstruction. In a previous report, mechanical obstruction of the urinary tract was suspected when the pelvic width was over 1·3 cm (d’Anjou and others 2011). However, despite severe pyelectasia, this case had no mechanical obstruction. Primary pyonephrosis arising from pyelonephritis should be included in the differential diagnosis even when the renal pelvis is significantly dilated and filled with echogenic sludge without marked obstructive lesions.
Jihye Choi 1 and Junghee Yoon *