Renal agenesis

From Dog

Renal agenesis is a congenital defect characterized by the lack of one or both kidneys.

This condition is rare in dogs and is always accompanied by ureteral aplasia and infrequently, urinary bladder hypoplasia[1].

Uterine aplastic or hypolastic anomalies may also coexist in teh same dog, such as unicornuate uterus or uterine segmental agenesis[2].

Bilaterally affected dogs rare live beyond 4 - 6 weeks of age[3][4], but unilateral renal agenesis may be asymptomatic in dogs and an incidental finding during investigation of incontinence or suspected ectopic ureters[5].

Clinically affected dogs with unilateral renal agenesis usually present with signs of urinary incontinence, polyuria, polydipsia and dehydration.

Blood results may show elevated creatinine and hyperkalemia consistent with chronic renal disease[6].

Ultrasonography and excretory urographies are usually suggestive of this disease but definitive diagnosis often necessitates exploratory laparotomy.

A differential diagnosis would include urolithiasis, renal hypoplasia of Boxers[7], X-linked hereditary nephropathy, polycystic kidney disease and renal cystadenoma or cystadenocarcinoma associated with dermatofibrosis in German Shepherds[8].

Unilateral renal agenesis is often an incidental finding at exploratory laparotomy and nephrectomy is rarely indicated due to the small size of the affected kidney. Dogs with chronic renal disease in association with this condition require specific renal support.


  1. Agut A et al (2002) Unilateral renal agenesis associated with additional congenital abnormalities of the urinary tract in a Pekingese bitch. J Small Anim Pract 43(1):32-35
  2. McIntyre RL et al (2010) Developmental uterine anomalies in cats and dogs undergoing elective ovariohysterectomy. J Am Vet Med Assoc 237(5):542-546
  3. Brownie CF et al (1988) Bilateral renal agenesis in two litters of Shetland sheepdogs. Vet Hum Toxicol 30(5):483-485
  4. Yates GH et al (2007) Bilateral renal agenesis in two cavalier King Charles spaniels. Vet Rec 160(19):672
  5. Taney KG et al (2003) Bilateral ectopic ureters in a male dog with unilateral renal agenesis. J Am Vet Med Assoc 223(6):817-820
  6. Diez-Prieto I et al (2001) Diagnosis of renal agenesis in a beagle. J Small Anim Pract 42(12):599-602
  7. Kolbjørnsen O et al (2008) End-stage kidney disease probably due to reflux nephropathy with segmental hypoplasia (Ask-Upmark kidney) in young Boxer dogs in Norway. A retrospective study. Vet Pathol 45(4):467-474
  8. Zanatta M et al (2012) Nodular Dermatofibrosis in a Dog without a Renal Tumour or a Mutation in the Folliculin Gene. J Comp Pathol Aug 4