CASE REPORT Ectopic cross ureter with uterus didelphys in a lamb Mohammad Naser Nazem 1 & Reza Kheirandish 2 Received: 7 April 2015 /Accepted: 9 November 2015 /Published online: 17 November 2015 # Springer-Verlag London 2015 Abstract The development and incorporation of the ureteric bud into the developing urinary bladder is a complex process, which is simultaneously influenced by events occurring in the development of other systems in the perineum. Knowledge of the embryology of the ureteric bud and associated Wolffian duct is the key to understand the development of the entire genitourinary system. In this article, we have reported and discussed a 1-day dead lamb with congenital ectopic ureter, open urachal sinus and uterus didelphys. Keyword Ectopic ureter . Urachal sinus . Uterus didelphys . Lamb Introduction Congenital anomalies of the kidney and urinary tract (CAKUT) are a family of diseases with a diverse anatomical spectrum. They include kidney anomalies and ureteropelvic anomalies such as ectopic ureteral orifice and anomalies of the bladder and urethra. It is also worth mentioning that these anomalies take a familiar pattern, showing incomplete and variable penetrance (Miyazaki and Ichikawa 2003). The urachus is a tubular three-layered structure that runs upward between peritoneum and transversalis fascia from the anterior dome of the bladder toward the umbilicus. Failure of the urachal lumen to close will result in one of several presen- tations of urachal anomalies (Simforoosh 1987). However, in a small proportion of adults, patency with the urinary bladder persists (Frangandreas et al. 2002). Urachal lesions can be classified into the patent urachus, urachal sinus, vesicourachal diverticulum, urachal cyst and alternating sinus. For example, in the vesicourachal divertic- ulum, the lower end of the urachus remains connected to the lumen of the bladder (Frangandreas et al. 2002). Uterus didelphys involves a double uterus with a true dou- ble cervix and a vaginal portion (Aiello 1988; Li et al. 2000); however, it does not always affect fertility (McEntee 1990). These cases can conceive normally but may show dystocia due to a foetal limb entering each cervical canal (Arthur et al. 1992). Case report In March 2014, a 1-day dead female lamb was referred to the veterinary clinic, Faculty of Veterinary Medicine, Shahid Bahonar University, Kerman, Iran, for postmortem examina- tion to determine the cause of death. Clinical findings showed some urogenital abnormalities. According to observations, there were two true kidneys with their true ureters. Both kidneys were located in their normal positions. At the renal hili, both ureters exited the kidneys, but their structures were abnormal and originated from the urachus (Fig. 1). The urachal duct junction to the umbilical cord and umbilical region was normal, but there was urinary leakage at the umbilicus where an open urachal sinus was seen. Ureters were the first ducts inserted symmetrically into the urachus (Fig. 1). A few millimetres after that, two branches * Mohammad Naser Nazem nnazem@uk.ac.ir 1 Department of Basic science, School of Veterinary Medicine, Shahid Bahonar University of Kerman, P. O. Box: 76169133, Kerman, Iran 2 Department of Pathobiology, School of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran Comp Clin Pathol (2016) 25:251–255 DOI 10.1007/s00580-015-2200-2