Foal umbilical

Just after the foal is born the placenta detaches from the foal leaving a small stump. That stump should be dipped in iodine (non bubbling) to prevent infection.

Sometimes when the placenta separates the foal can get a small tear internally near the umbilical cord. Or the foal can cough too hard causing a tear, or play too hard, or get a small infection and have it tear. This can result in hernia or abscess.

Hernias are common and usually not a big concern. If there is 1-2 fingers and no food is stuck in the protruding pouch most vets will suggest to wait and see. While you are waiting you can massage it back up a few times a day. most of the time the foals will recover as they grow. There are also cases of adult horses with the same size hernia that do nothing about it.

If there are more than 2 fingers space and any food or debris is stuck in the pouch then it needs to be addressed sooner rather than later. If food gets stuck in there or the intestines gets trapped in the hole and can't stay fluid then the tissue will get infected and cause bigger issues.

If the hernia is harder and you can't "push it back up in there" then it might be an abscess. This also has to be addressed quickly because it's an infection. In some cases antibiotics work but in others it has to be surgically removed/treated then followed up with antibiotics.

Umbilical Abscess