The umbilical cord and the umbilicus
The umbilical cord consists of different structures, firstly, an umbilical vein flowing from the placenta to the fetus and secondly, umbilical arteries flowing from the fetus back to the placenta.
During gestation, the umbilical cord ensures transfer of oxygen and nutrients from the mare to the fetus through the umbilical vein. It also allows the fetus to dispose of its waste products through two umbilical arteries and the urachus.
During birth, the umbilical cord remains attached to the placenta, with 4-5 twists over its length. Ideally, it will stay intact for a few seconds to minutes before breaking, allowing the remaining blood in the placenta to flow into the foal. This will provide the foal with extra nutrients and fluid.
The umbilical cord breaks when the mare stands up or following foal movements and usually does not require human intervention. In the rare circumstance that it does not break, it can be manually broken at a length of about 1 cm from the foal’s umbilicus. When the cord has broken, it is good to check for bleeding, and to clamp the umbilicus if this occurs.
In the following days after birth, the umbilical stump of the foal should be disinfected with diluted iodine or chlorhexidine solution to prevent bacterial infection. The umbilical stump should dry up in a couple of days and eventually fall off.
In the case of swelling, bleeding, secretions (urine or pus), a veterinarian should check the umbilicus and perform an ultrasonography.
Pictured top: Normal umbilical cord after birth