HIND PRESENTATIONS WITH BACK TURNED SIDEWAYS OR DOWNWARD.--These are the counterparts of similar anterior presentations and are to be managed in the same way.
PRESENTATION OF THE BACK.--This is rare, yet not unknown, the foal being bent upon itself with the back, recognizable by its sharp row of spines, presented at the entrance of the pelvis and the head and all four feet turned back into the womb. (Plate XVI, fig. 1.) The body of the fetus may be extended across the opening transversely, so that the head corresponds to one side (right or left), or it may be vertical, with the head above or below.
In any such position the object should be to push the body of the fetus forward and upward or to one side, as may best promise to bring up the fore or hind extremities, and bring the latter into the passage so as to constitute a normal anterior or posterior presentation. This turning of the fetus may be favored by a given position of the mother, by the free use of oil or lard on the surface of the fetus, and by the use of a propeller.
PRESENTATION OF BREAST AND ABDOMEN.--This is the reverse of the back presentation, the foal being extended across in front of the pelvic opening, but with the belly turned toward the passages and with all four feet engaged in the passage. (Plate XVI, fig. 2.) The most promising course is to secure the hind feet with nooses and then push the fore feet forward into the womb. As soon as the fore feet are pushed forward clear of the brim of the pelvis, traction is made on the hind feet so as to bring the thighs into the passage and prevent the reentrance of the fore limbs. If it proves difficult to push the fore limbs back, a noose may be passed around the fetlock of each and the cord drawn through the eye of a rope carrier, by means of which the members may be easily pushed back.
Embryotomy consists in the dissection of the fetus, so as to reduce its bulk and allow of its exit through the pelvis. The indications for its adoption have been furnished in the foregoing pages. The operation will vary in different cases according to the necessity for the removal of one or more parts in order to secure the requisite reduction in size. Thus it may be needful to remove head and neck, one fore limb or both, one hind limb or both, to remove different parts of the trunk, or to remove superfluous (monstrous) parts. Some of the simplest operations in embryotomy (incision of the head in hydrocephalus, incision of the belly in dropsy) have already been described. It remains to notice the more difficult procedures which can be best undertaken by the skilled anatomist.