These include all general presentations, yet other subsidiary ones will at once occur to the attentive reader. Thus, in each anterior or posterior presentation, with the back of the calf turned downward or to one side, the case may be complicated by the bending back of one or more members as a whole or at the joint just above the shank bones (knee or hock). So also in such anterior presentation the head may be turned back.
Head and fore feet presented—Back turned to one side.—The calf has a greater diameter from above down (spine to breastbone) than it has from side to side, and the same is true of the passage of the pelvis of the cow, which measures, on an average, 8-7/10 inches from above downward and 7-9/10 inches from side to side. Hence the calf passes most easily with its back upward, and when turned with its back to one side calving is always tardy and may be difficult or impossible. The obvious remedy is to rotate the calf on its own axis until its spine turns toward the spine of the cow. The operation is not difficult if the body of the calf is not yet fixed in the passages. The presenting feet are twisted over each other in the direction desired, and this is continued until the head and spine have assumed their proper place. If the body is firmly engaged in the passages the skin of the whole engaged portion should be freely lubricated with lard, and the limbs and head twisted over each other as above. The limbs may be twisted by an assistant when the head is manipulated by the operator, who drags on the rope turned halfway round the limbs and assists in the rotation with his other hand in the passages.
Head and fore feet presented—Back turned down toward the udder.—This position ([Pl. XVI], fig. 6) is unnatural, and the parturition is difficult for two reasons: First, the natural curvature of the fetus is opposed to the natural curvature of the passages; and, second, the thickest part of the body of the calf (the upper) is engaged in the narrowest part of the passage of the pelvis (the lower). Yet unless the calf is especially large and the pelvis of the cow narrow, parturition may usually be accomplished in this way spontaneously or with very little assistance in the way of traction on the limbs. If this can not be accomplished, two courses are open: First, to rotate the calf as when the back is turned to one side; second, to push back the presenting fore limbs and head and search for and bring up the hind limbs, when the presentation will be a natural, posterior one.
Presentation of the hind feet with the back turned to one side or downward.—These are the exact counterparts of the two conditions last described, are beset with similar drawbacks, and are to be dealt with on the same general principles. ([Pl. XVII], fig. 4.) With the back turned to one side the body should be rotated until the back turns toward the spine of the dam, and with the back turned down it must be extracted in that position (care being taken that the feet do not perforate the roof of the vagina) or it must be rotated on its own axis until the back turns upward, or the hind limbs must be pushed back and the fore limbs and head advanced, when the presentation will be a natural anterior one.
Impaction of twins in the passage.—It is very rare to have twins enter the passages together so as to become firmly impacted. As a rule, each of the twins has its own separate membranes, and as the water bags of one will naturally first enter and be the first to burst, so the calf which occupied those membranes will be the first to enter the passage and the other will be thereby excluded. When the membranes of both have burst without either calf having become engaged in the pelvis, it becomes possible for the fore legs of one and the hind legs of the other to enter at one time, and if the straining is very violent they may become firmly impacted. ([Pl. XVIII], fig. 1.) The condition may be recognized by the fact that two of the presenting feet have their fronts turned forward, while the two others have their fronts turned backward. If the four feet belonged to one natural calf, they would all have the same direction. By means of this difference in direction we can easily select the two feet of one calf, place running nooses upon them just above the hoofs or fetlocks, and have an assistant drag upon the ropes while the feet of the other calf are pushed back. In selecting one of the twins to come first several considerations should have weight. The one that is most advanced in the passage is, of course, the first choice. Though the fore feet of one are presented, yet if the head is not in place the calf presenting by its hind feet is to be chosen as being less liable to obstruct. Again, if for either calf one limb only is presented and the other missing, the one presenting two feet should be selected to come first. As soon as one calf has been advanced so as to occupy the pelvis the other will be crowded back so that it will not seriously obstruct.
Fore limbs curved at the knee—Limbs sprawling outward.—In this case not only are the knees somewhat bent in a curve, but the calf has a position as if it rested on its breastbone, while the legs were drawn apart and directed to the right and left. The shoulder blades being drawn outward from the chest and the elbows turned out, the muscles extending from the trunk to the limb are unduly stretched and keep the knees bent and the feet directed outward so as to press on the sides of the passages. They become retarded in their progress as compared with the more rapidly advancing head, and may bruise or even lacerate the walls of the vagina. It would seem easy to rectify this by extending the legs, but the already tense and overstretched muscles operate against extension in the present position, and it is not easy to rotate the limbs so as to apply the shoulder flat against the side of the chest. Under these circumstances a repeller ([Pl. XX], fig. 7) may be planted in the breast and the body of the calf pushed backward into the womb, when the limbs will extend easily under traction and the presentation becomes at once natural.
Fore limbs curved at knee—Flexor tendons shortening.—In this case the feet will press against the floor of the pelvis though the limb has no outward direction, and the shoulder meanwhile presses against the roof of the same passage. Unless the knees can be sufficiently straightened by force a knife must be used to cut across the cords behind the knee, when the limbs may be straightened sufficiently.
Fore limbs flexed at knee—Flexor tendons unshortened.—This is mostly seen in cases in which the body of the calf is in the proper position, its back being turned up toward the back of the dam, and in cows with a drooping abdomen. The feet have been supposed to catch beneath the brim of the pelvis, and being retarded while the head advances into the passages, they get bent at the knee and the nose and knees present. ([Pl. XVI], fig. 2.) The calf, however, is not an inanimate body advanced by the mere contraction of the womb, but it moves its limbs freely under the stimulus of the unwonted compression, and in moving the feet as they are advanced they slip down over the pelvic brim and finding no other firm support they bend back until, under the impulsion, they can no longer straighten out again. The knees, therefore, advance with the neck and head, but the feet remain bent back. The result is that the upper part of the limb is also flexed, and the shoulder blade and arm bone with their masses of investing muscles are carried backward and applied on the side of the chest, greatly increasing the bulk of this already bulky part. As the elbow is carried back on the side of the chest, the forearm from elbow to knee further increases the superadded masses of the shoulder and renders it difficult or impossible to drag the mass through the passages. When the fore limbs are fully extended, on the contrary, the shoulder blade is extended forward on the smallest and narrowest part of the chest, the arm bone with its muscles is in great part applied against the side of the back part of the neck, and the forearm is continued forward by the side of the head so that the nose lies between the knees. In this natural presentation the presenting body of the calf forms a long wedge or cone, the increase of which is slow and gradual until it reaches the middle of the chest.
The difficulty of extending the fore limbs will be in proportion to the advance of the head through the pelvic cavity. In the early stage all that is necessary may be to introduce the oiled hand, the left one for the right leg or the right one for the left, and passing the hand from the knee on to the foot to seize the foot in the palm, bend it forcibly on the fetlock, and lift it up over the brim of the pelvis, the knee being, of course, pressed upward against the spine. As soon as the foot has been raised above the brim of the pelvis (into the passage) the limb can be straightened out with the greatest ease.