The breech of the foetus may be presented either with the hind-legs in the passage (fig. 551) or projected forward under the abdomen (fig. 552). In the former position delivery may be effected without assistance, but it is always desirable to afford help promptly where the least difficulty arises. This position is the most favourable breech form of presentation, since it requires no readjustment of parts. All that is necessary is to supplement the natural force of the throes with manual assistance from without.
It is otherwise where the hocks are flexed and presented with the breech, and the legs extend forward under the belly (fig. 552). In this presentation there is danger of the parts being wedged in the pelvis, and so fixed as to render a proper adjustment difficult if not impossible. Before delivery can be effected in this case the direction of the hind-limbs must be changed and they must be brought into the passage. To effect this it is necessary that room be provided by forcing the buttocks in a forward direction so as to clear a space for bringing up the hind-limbs. In performing this task, advantage will be obtained if the hind extremities of the mare be raised by underpacking with litter or some other suitable means. A forward and downward inclination will thus be given to the foetus, and the resistance to pressure from behind thereby reduced. When this has been done, an attempt should be made to force the body of the foal forward, either by means of the hand or a crutch (fig. 558) applied to the buttocks immediately below the tail. In this connection it is necessary to point out that the force employed should not be sudden and spasmodic, but steady, continuous, and progressive. The intervals between the throes are periods when the foetus will yield most to pressure, and the advantage gained at these times should not be lost, if possible, when straining returns.
Fig. 552. - Breech and Hocks presented.
Room having been thus provided, an attempt should now be made to bring the hind-legs into position for delivery. For this purpose the palm of the hand should be placed against the under side of the point of the hock, and pressure made in a forward and slightly upward direction upon the second thigh. If by a little manoeuvring a cord can be placed round the bend of the hock, it should be done and handed to an assistant, who will be able to render considerable help by pulling the limb backwards when the right time comes.
The operator should now grasp the shin-bone, and with such help as his assistant can give him, draw the leg towards the pelvic inlet. As soon as the pastern or the foot can be reached, the fetlock-joint should be forcibly flexed and the leg lifted into the passage. Before this can be clone it may be necessary to pass a cord round the pastern and bring traction to bear upon it, while the operator presses the point of the hock in an upward and forward direction. After one limb has been adjusted the other must be dealt with in the same manner.
Fig. 553. - Breech presentation, Legs extended beneath Abdomen.
A still more troublesome and dangerous breech presentation is that where the hind-legs, instead of being flexed as in the case referred to above, are carried forward and downward towards the fore-limbs, and the thigh bent upon the pelvis allows the croup and buttocks to be presented (fig. 553).
Unless this misplacement is promptly recognized and corrected, the difficulty will be aggravated by the straining, which, while forcing the breech backward into the pelvis, causes the hind-limbs to be moved farther forward at the same time, thus adding to the already serious difficulty of the case. Here " the rational indication is, of course, to extend the limbs of the foetus backwards, as in ordinary breech presentation (fig. 551), and to give these and the body a direction in harmony with the axis and dimensions of the pelvic inlet, so that birth may be effected by the combined efforts of the mother and the obstetrist". But this indication is often most difficult to fulfil, though in some instances it is possible when labour is not too advanced, and when the foetus, still in the abdominal cavity, is movable, and can be pushed sufficiently from the inlet to allow the lower part of the limbs to be seized and brought into the vagina.
Pushing the foetus as far into the abdomen as possible, one of the limbs is seized above the hock, and the thigh flexed as completely as circumstances will permit, by lifting that joint towards the mother's sacrum. Still pushing the foetus off by means of the repeller or crutch, the hand is passed down to the hoof until the toe is reached and enclosed in the palm; by adopting this precaution danger of injury to the uterus or vagina is averted. Then the foot is brought into the passage by flexing all the joints on each other. Again, pushing the foetus forward, the same manoeuvre is repeated with the other limb, if necessary, and delivery is proceeded with.