Special Report on Diseases of Cattle - LightNovelsOnl.com
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MONSTROSITY IN THE CALF.
As a monstrous development in the calf may hinder calving, it is well to consider shortly the different directions in which these deviations from the natural form appear. Their origin and significance will be rendered clearer if we divide them according to the fault of development in individual cases. Monsters are such--
(1) From absence of parts--absence of head, limb, or other organ--arrested development.
(2) From some organ being unnaturally small, as a dwarfed head, limb, trunk, etc.--arrested development.
(3) From unnatural division of parts--cleft lips, palate, head, trunk, limbs, etc.--abnormal growth.
(4) From the absence of natural divisions--absence of mouth, nose, eye, a.n.u.s; the cloven foot of ox or pig becomes solid, like that of the horse, etc.--confluence of parts which are rightfully separate.
(5) From the fusion of parts--both eyes replaced by central one, both nostrils merged into one central opening, etc.--confluence of parts.
(6) From unnatural position or form of parts--curved nose, neck, back, limbs, etc.--lack of balance in the growth of muscles during development.
(7) From excessive growth of one or more organs--enormous size of head, double p.e.n.i.s, superfluous digits, etc.--redundancy of growth at given points.
(8) From imperfect differentiation of the s.e.xual organs--hermaphrodites (organs intermediate between male and female), male organs with certain feminine characters, female organs with certain well-marked male characters.
(9) From the doubling of parts or of the entire body--double monsters, doubled heads, doubled bodies, extra limbs, etc.--redundant development.
(Pl. XIX, figs. 1, 2, 3.)
_Causes._--The causes of monstrosities are varied. Some, like extra digits, lack of horns, etc., run in families, which produce them with absolute certainty when bred in the direct line, although they were originally acquired peculiarities which have merely been fixed by long habit in successive generations. The earliest horse had five toes, and even the most recent fossil horse had three toes, of which the two lateral ones are still represented in the modern animal by the two splint bones. Yet if our horse develops an extra toe it is p.r.o.nounced a monstrosity. A more genuine monstrosity is the solid-hoofed pig, in which two toes have been merged into one. Another of the same kind is the solid shank bone of the ox, which consists of two bones united into one, but which are still found apart in the early fetus. Though originally acquired peculiarities, they now breed as invariably as color or form.
Other monstrosities seem to have begun in too close breeding, by which the powers of symmetrical development are impaired, just as the procreative power weakens under continuous breeding from the closest blood relations. A monstrosity consisting in the absence of an organ often depends on a simple lack of development, the result of disease or injury, as a young bone is permanently shortened by being broken across the soft part between the shaft and the end, the only part where increase in length can take place.
As the result of the injury the soft, growing layer becomes prematurely hard and all increase in length at that end of the bone ceases. This will account for some cases of absence of eye, limb, or other organ.
Sometimes a monstrosity is owing to the inclosure of one ovum in another while the latter is still but a soft ma.s.s of cells and can easily close around the first. Here each ovum has an independent life; they develop simultaneously, only the outer one having direct connection with the womb and being furnished with abundant nourishment advances most rapidly and perfectly, while the inclosed and starved ovum is dwarfed and imperfect often to the last degree.
In many cases of excess of parts the extra part or member is manifestly derived from the same ovum, and even the same part of the ovum, being merely the effect of a redundancy and vagary of growth. Such cases include most instances of extra digits or other organs, and even of double monsters, as manifested by the fact that such extra organs grow from the normal identical organs. Hence the extra digit is attached to the normal digit, the extra head to the one neck, the extra tail to the croup, extra teeth to the existing teeth, and even two similarly formed bodies are attached by some point common to both, as the navels, breastbones, backs, etc. (Pl. XIX, figs. 1, 2, 3.) This shows that both have been derived from the same primitive layer of the embryo, which possessed the plastic power of building up a given structure or set of organs. An inclosed ovum, on the other hand, has no such ident.i.ty or similarity of structure to the part with which it is connected, showing an evident primary independence of both life and the power of building tissues and organs. The power of determining extra growth along a given natural line is very highly developed in the early embryo and is equally manifest in the mature examples of some of the lower forms of animal life. Thus a newt will grow a new tail when that member has been cut off, and a starfish will develop as many new starfishes as the pieces made by cutting up the original one. This power of growth in the embryo and in the lower form of animals is comparable to the branching out again of a tree at the places from which branches have been lopped. The presence of this vegetablelike power of growth in the embryo accounts for most double monsters.
The influence of disease in modifying growth in the early embryo, increasing, decreasing, distorting, etc., is well ill.u.s.trated in the experiments of St. Hilaire and Valentine in varnis.h.i.+ng, shaking, or otherwise disturbing the connections of eggs and thereby producing monstrosities. One can easily understand how inflammations and other causes of disturbed circulation in the womb, fetal membranes, or fetus would cause similar distortions and variations in the growing fetus. It is doubtless largely in the same way that certain mental disturbances of a very susceptible dam affect the appearance of the progeny. The monstrosities which seriously interfere with calving are mainly such as consist in extra members or head, which can not be admitted into the pa.s.sages at the same time, where some organ of the body has attained extra size, where a blighted ovum has been inclosed in the body of a more perfect one, or where the body or limbs are so contracted or twisted that the calf must enter the pa.s.sages doubled up.
_Treatment._--Extraction is sometimes possible by straightening the distorted members by the force of traction; in other cases the muscles or tendons must be cut across on the side to which the body or limbs are bent to allow of such straightening. Thus, the muscles on the concave side of a wry neck or the cords behind the shank bones of a contracted limb may be cut to allow of these parts being brought into the pa.s.sages, and there will still be wanting the methods demanded for bringing up missing limbs or head, for which see paragraphs below. In most cases of monstrosity by excess of overgrowth it becomes necessary to cut off the supernumerary or overdeveloped parts, and the same general principles must be followed as laid down in "Embryotomy" (p. 202).
WRONG PRESENTATIONS OF THE CALF.
The following is a list of abnormal presentations of the calf:
Simultaneous presentation of twins.
A { {Limbs curved at the knee. Flexor tendons shortened.
n {Fore Limbs{Limb crossed over the back of the neck.
t { {Limb bent back at the knee.
e { {Limb bent back from the shoulder.
r { i { {Head bent downward on the neck.
o P { {Head and neck turned downward beneath the breast.
r r {Head {Head turned to one side upon the side of the neck.
e { {Head and neck turned back on the side of the chest and s { { abdomen.
e { {Head turned upward and backward on the back.
n { t { {Hind limbs rotated outward. Toes and stifles turned a { { outward.
t {Hind Limbs{Hind limbs bent forward, their feet resting in the pelvis.
i { o {Transverse{Back of the calf turned to the right or left side.
n { s {Inverted {Back of the calf turned to the floor of the pelvis and { { udder.
P P { o r { {Hind limb bent on itself at the hock. Hock and b.u.t.tocks s e {Hind Limbs{ present.
t s { {Hind limb bent at the hips. b.u.t.tocks present.
e e { r n {Transverse{Back of calf turned to the right or left side.
i t { o a {Inverted {Back of calf turned to the floor of the pelvis and udder.
r t { i { o { n { {Head up toward the spine, croup {Position of calf vertical { toward udder.
T { { {Head down toward udder, croup r {Back { { toward spine.
u P {and { n r {loins { {Head toward the right side, k e {presented.{Position of calf transverse{ croup toward the left.
s { { e { { {Head toward the left side, n { { { croup toward the right.
t { { a { { t {Breast { {Head toward right side, croup i {and {Position of calf transverse{ toward left.
o {abdomen { {Head toward left side, croup n {presented.{ { toward right.
s {
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 pa.s.sage 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 pa.s.ses 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 pa.s.sages. The presenting feet are twisted over each other in the direction desired, and this is continued until the head and spine have a.s.sumed their proper place. If the body is firmly engaged in the pa.s.sages 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 a.s.sistant when the head is manipulated by the operator, who drags on the rope turned halfway round the limbs and a.s.sists in the rotation with his other hand in the pa.s.sages.
_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 pa.s.sages; and, second, the thickest part of the body of the calf (the upper) is engaged in the narrowest part of the pa.s.sage 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 a.s.sistance 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 v.a.g.i.n.a) 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 pa.s.sage._--It is very rare to have twins enter the pa.s.sages 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 pa.s.sage 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 a.s.sistant 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 pa.s.sage 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 pa.s.sages. They become r.e.t.a.r.ded in their progress as compared with the more rapidly advancing head, and may bruise or even lacerate the walls of the v.a.g.i.n.a. 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 circ.u.mstances 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 pa.s.sage. 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 r.e.t.a.r.ded while the head advances into the pa.s.sages, 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 ma.s.ses 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 ma.s.ses of the shoulder and renders it difficult or impossible to drag the ma.s.s through the pa.s.sages. 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 pa.s.sing 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 pa.s.sage) the limb can be straightened out with the greatest ease.
When, however, the shoulders are already engaging in the pelvis the feet can not thus be lifted up, and to gain room a repeller (Pl. XX, fig. 7) must be used to push back the body of the calf. This is an instrument with a long, straight stem, divided at the end into two short branches (2 to 3 inches long) united to the stem by hinges so that they can be brought into a line with the stem for introduction into the womb and then spread to be implanted in the breast. In the absence of a repeller a smooth, round, fork handle may be used, the p.r.o.ngs having been removed from the other end. A third device is to have an a.s.sistant strip his arm to the shoulder and, standing back to back with the operator, to introduce his right arm into the pa.s.sages along with the operator's left (or vice versa) and push back the body of the calf while the operator seeks to bring up a limb. The repeller or staff having been planted safely in the breast of the calf, an a.s.sistant pushes upon it in a direction either forward or slightly upward, so as not only to follow the natural curve of the body and favor its turning in the line of that curve within the womb, but also to carry the shoulders upward toward the spine and obtain more room for bringing up the missing feet. It is good policy, first, to put a halter (Pl. XXI, figs.
4_a_ and 4_b_) on the head or a noose (Pl. XXI, fig. 3) on the lower jaw and a rope round each limb at the knee, so as to provide against the loss of any of these parts when the body is pushed back into the womb. This offers the further advantage that by dragging upon these ropes the body can be advanced in the pa.s.sage until the foot is reached, when the rope must be slackened and the repeller used to get room for bringing up the foot. If the cow is lying, the operator should first secure the foot on the upper side and then, if necessary, turn the cow on its opposite side so as to bring up the other.
In using the instruments some precautions are demanded. They must be invariably warmed before they are introduced, and they should be smeared with lard or oil to make them pa.s.s easily and without friction. The a.s.sistant who is pus.h.i.+ng on the instrument must be warned to stop if at any time resistance gives way. This may mean the turning of the fetus, in which case the object of repulsion has been accomplished, but much more probably it implies the displacement of the instrument from the body of the fetus, and unguarded pressure may drive it through the walls of the womb.
When the calf enters the pa.s.sage with its back turned down toward the belly and udder, the bending back of the fore limbs is rare, probably because the feet can find a straighter and more nearly uniform surface of resistance in the upper wall of the womb and the backbone, and do not slide over a crest into an open cavity, as they do over the brim of the pelvis. The weight of the calf, too, gravitating downward, leaves more room for the straightening of the bent limbs, so that the desired relief is much more easily secured.
The manipulation is the same in principle, only one must add the precaution of a steady traction on the feet in extraction, lest, owing to the adverse curvature of the fetus, the hoofs are suddenly forced through the roof of the v.a.g.i.n.a, and, perhaps, the r.e.c.t.u.m as well, during a specially powerful labor pain.