Correction of Retained Head.
Due to the length of the neck of the foal it may be impossible to retrieve the head. Once the foal is dead one end of the fetotomy wire can be placed around the base of neck of the fetus, and rethreaded in the open channel of the fetatome. The severed neck and head are then backed out of the birth canal. As a rule of thumb no more than two or three fetotomy cuts should be made in the mare to minimize trauma to the cervix and vagina of the mare which leads to the formation of adhesions.
Bierschwal CJ and deBois CHW (1975)