Ectopic kidney

From Dog

Ectopic kidney is a congenital disease of dogs characterized by anatomically unusual location of one or both kidneys.

This condition is caused by a delay in the migration of the kidney into the lumbar region or the persistence of the embryological structures[1].

Other aberrant malformations can also occur such as duplex kidneys or ectopic dysplastic kidneys. Rare human cases of intrathoracic kidneys have also been reported[2], but not in dogs.

The abnormal insertion of the ureter, rotation anomalies, and different localization of the kidneys predispose the ectopic kidney to vascular insufficiency[3], glomerulonephritis, hydronephrosis, ureteroliths[4] or ureteral stenosis.

Some cases are diagnosed accidentally during routine abdominal ultrasonography and are clinically asymptomatic.

Clinically affected dogs often present with cystitis and chronic renal disease[5] due to malfunctioning renal tissue.

Diagnosis is based on presenting clinical signs, abdominal palpation of a mass in an usual location, and imaging studies such as ultrasonography and excretory urography.

Blood tests may reveal azotemia and hyperkalemia.

Urinalysis and urine cultures should be performed to exclude urinary tract infections.

A differential diagnosis include other congenital renal diseases such as ectopic ureters, renal dysplasia and renal agenesis[6].

In unilaterally cases in dogs with signs of renal compromise in the affected kidney, treatment invariably involves nephrectomy and ureterectomy due to renal disease, providing normal function is observed in teh ipsilateral kidney.


  1. Zafar FS & Lingeman JS (1996) Value of laparoscopy in the management of calculi complicating renal malformations. J Endourol 10:379–383
  2. Dieguez-Santiesteban N & Lugo-Vicente H (2012) Intrathoracic kidney in a child: case report and review of literature. Bol Asoc Med P R 104(3):47-50
  3. Kulkarni R (2013) A right ectopic kidney with bilateral multiple anomalies of the renal vasculature - a case report. J Clin Diagn Res 7(1):150-153
  4. Bozkurt IH et al (2012) Retroperitoneal laparoscopic pyelolithotomy in an ectopic pelvic kidney. JSLS 16(2):325-328
  5. Choi J et al (2012) Simple ectopic kidney in three dogs. J Vet Med Sci 74(10):1373-1375
  6. Yoon HY et al (2010) Bilateral ureteral ectopia with renal dysplasia and urolithiasis in a dog. J Am Anim Hosp Assoc 46(3):209-214