Unilateral hydronephrosis

Unilateral hydronephrosis in an 8-year-old Staffordshire Terrier bitch. The kidney is much enlarged, with a feeling of fluctuation to the touch and abundant loss of cloudy fluid when cut. After removal of this fluid, the atrophy of the renal parenchyma became evident, with only a roughly 2mm margin of renal cortex left adhering to the capsule. The ureter appears distended in two thirds of its cranial length, becoming suddenly very narrow in its caudal third. This fibrotic stenosis of the ureter stopped the flow of urine, which accumulated in the calyx and compressed the renal parenchyma, leading to its destruction.