Case Description: A ten-year-old neutered female terrier dog was referred to the Tehran-Azma Veterinary Diagnostic Center for history of too late recovery too late after ovariohysterectomy.
Clinical Finding: Blood chemical laboratory tests revealed high serum BUN, maximum concentration of creatinine and decreased of serum albumin. Sonographically, there was an anechoic cyst-like structurein the right side of the bladder trigone. The abnormality appeared to be a “cyst within a cyst”, which is a characteristic ultrasonographic feature of ureterocele in humans.
Treatment and Outcome: The case referred to surgery section and underwent total right kidney dissection and ureterocele tearing.

Clinical Relevance: An ureterocele is a congenital cystic dilation of the submucosal portion of the distal ureter and ultrasonography is a useful means of diagnosis of urogenital disease and disorders.