Cross-species summary: The urachus is a canal present in the foetus, connecting the bladder with the allantois via the navel. It normally disappears after birth. A patent urachus is one which persists after birth, allowing urine to drip out of the bladder through the umbilicus.

Species in which this phene is found:
dog (Canis lupus familiaris)
domestic cat (Felis catus)
mountain zebra (Equus zebra)
white rhinoceros (Ceratotherium simum)
sheep (Ovis aries)