Special Report on Diseases of Cattle - LightNovelsOnl.com
You're reading novel online at LightNovelsOnl.com. Please use the follow button to get notifications about your favorite novels and its latest chapters so you can come back anytime and won't miss anything.
POLYPUS OF THE v.a.g.i.n.a OR UTERUS.
A polypus is a tumor growing from the mucous membrane, and often connected to it by a narrow neck. A definite cause can not always be a.s.signed. If growing in the v.a.g.i.n.a, a polypus may project as a reddish, rounded tumor from the v.u.l.v.a, especially during the act of pa.s.sing water. It can be distinguished from descent of the womb by the absence of the orifice of that cavity, which can be felt by the oiled hand beyond the tumor in the depth of the v.a.g.i.n.a. From a v.a.g.i.n.al hernia caused by the protrusion of some abdominal organ enveloped by the relaxed wall of the v.a.g.i.n.a it may be distinguished by its persistence, its firm substance, and the impossibility of returning it into the abdomen by pressure. A hernia containing a portion of bowel gurgles when handled and can be completely effaced by pressure, the gut pa.s.sing into the abdomen.
A polypus in the womb is less easily recognized. At the time of calving it may be felt through the open mouth of the womb and recognized by the educated touch (it must be carefully distinguished from the mushroom-formed cotyledons (Pl. XIII, fig. 2), to which in ruminants the fetal membranes are attached). At other times, unless the womb is opened in the effort to expel it, the polypus can be detected only by examining the womb with the oiled hand introduced through the r.e.c.t.u.m.
Polypi may cause a mucopurulent discharge or they may only be suspected when they prove an obstacle to parturition. The best way to remove them is to put the chain of an ecraseur around the neck, or pedicle, of the tumor and tear it through; or the narrow neck may be torn through by the emasculator, or in an emergency it may be twisted through by rotating the tumor on its axis. The removal of the tumor will allow calving to proceed; after this the sore may be treated by a daily injection of one-half dram sulphate of zinc, 1 dram carbolic acid, and 1 quart milk-warm water.
SIGNS OF PREGNANCY.
If a cow remains for three or four weeks after service without showing signs of heat (bulling), she is probably pregnant. There are very exceptional cases in which the well-fed cow will accept the bull weeks or months after actual conception, and others equally exceptional in which the well-thriven but unimpregnated female will refuse the male persistently, but these in no way invalidate the general rule.
The bull, no matter how vigorous or how ardent his s.e.xual instinct, can not be made to pay any attention to a cow which is not in heat; hence indications of pregnancy can be had from both the male and female side.
When she has conceived, the cow usually becomes more quiet and docile, and lays on flesh and fat more rapidly, especially during the first four months of gestation. The stimulus to digestion and nutrition created by the demands of the growing fetus, added to the quieter and more uneventful life, contributes to this result. Some feeders avail themselves of this disposition to prepare heifers and cows speedily for the butcher.
The enlargement of the abdomen, and its dropping so that it bulges below and to each side, while it falls in at the flank, between the outer angle of the hip bone and the last rib, are significant features which, though they may be caused by abdominal tumor or dropsy, are usually marks of pregnancy. From the same increasing weight of the abdomen the spine in the region of the loins sinks so that the bones of the croup seem to rise, especially back toward the root of the tail. In the early stages of pregnancy the udder develops slowly, and toward its completion quite rapidly. For a long time there is merely a sense of greater fullness when handled; the wrinkles in the skin become shallower and are effaced, and the teats are materially enlarged. Beginning a few weeks after conception, this tends to a steady development, though slight alternations in the sense of successive growth and shrinkage are not uncommon. In milking cows this does not hold, as the milk usually tends to a steady diminution and the udder shrinks slowly until near the completion of the period, when it undergoes its sudden, remarkable development, and yields at first a serous liquid and then the yellow colostrum, which coagulates when heated. As pregnancy advances the mucous membrane lining the v.u.l.v.a becomes swollen and of a darker, bluish-red hue; the mucous secretion also increases, becoming very abundant just before calving. When the feeding has not been altered or restricted, a steady diminution of the salts of lime excreted in the urine is an attendant on pregnancy, the lime being demanded for the growing body of the fetus.
After the fifth month the movements of the calf may often be observed in the right flank, nearly in front of the stifle, when the cow is drinking cold water. The sensation of cold on the side of the first stomach, which lies to the left and directly below the womb (Pl. I), stimulates the calf to active movements, which are detected on the sudden jerking outward of the abdominal wall as if from blows delivered from within. In a loose, pendent abdomen in the latter months of gestation the skin may often be seen pushed out at a sharp angle, irrespective of the period of drinking.
Another mode of examination through the flank is by touch. The palm of the hand is pressed strongly inward, about 8 inches in front of the stifle and a little below, several times in succession, and is then brought to rest with the pressure maintained. Presently there are felt distinct and characteristic movements of the fetus, which has been disturbed and roused to action. Another mode is to press the closed fist strongly inward in the same situation and hold it so, forming a deep indentation in the abdominal wall. Presently the knuckles are felt to be struck by a solid body, which is no other than the fetus that has been displaced to the left by the push of the hand, and now floats back in its liquid covering (amniotic fluid; see Pl. XII) downward and to the right.
Of all the modes of examination by touch, that done through the r.e.c.t.u.m gives the earliest satisfactory indications. The hand and arm, well oiled, are introduced, and the excrement having been removed if necessary, the palm of the hand is turned downward and the floor of the pelvis carefully examined. There will be felt in the median line the pear-shaped outline of the bladder, more or less full, rounded or tense, according to the quant.i.ty of urine it contains. Between this and the hand will be felt a soft, somewhat rounded tubular body, which divides in front into two smaller tubes or branches, extending to the right and left into the abdomen. This is the womb, which in its virgin, or unimpregnated, condition is of nearly uniform size from before backward, the main part or body being from 1-1/2 to 2 inches across, and the two anterior branches or horns being individually little over an inch wide. Immediately after conception the body and one of the horns begin to enlarge, the vacant horn remaining disproportionately small, and the enlargement will be most marked at one point, where a solid, rounded ma.s.s indicates the presence of the growing embryo. In case of twins, both horns are enlarged. At a more advanced stage, when the embryo begins to a.s.sume the form of the future animal, the rounded form gives place to a more or less irregular nodular ma.s.s, while later still the head, limbs, and body of the fetus may be distinctly made out. The chief source of fallacy is found in the very pendent abdomen of certain cows, into which in advanced gestation the fetus has dropped so low that it can not be felt by the hand in the r.e.c.t.u.m. The absence of the distinct outline of the vacant womb, however, and the clear indications obtained on external examination through the right flank will serve to prevent any mistake. The fetus may still be felt through the r.e.c.t.u.m if the abdomen is raised by a sheet pa.s.sed from side to side beneath it.
Still another sign is the beating of the fetal heart, which may be heard in the latter half of pregnancy when the ear is pressed on the flank in front of the right stifle or from that downward to the udder. The beats, which are best heard in the absence of rumbling, are about 120 a minute and easily distinguished from any bowel sounds by their perfect regularity.
DURATION OF PREGNANCY.
From extended statistics it is found that the average duration of pregnancy in the cow is 285 days. A calf born at the two hundred and fortieth day may live, and Dietrichs reported a case of a calf born on the three hundred and thirty-fifth day, and another was reported by the American Journal of Medical Science as having been born on the three hundred and thirty-sixth day. It is the general observation that in most cases of prolonged pregnancies the offspring are males. Lord Spencer found a preponderance of males between the two hundred and ninetieth and the three hundredth days, but strangely enough all born after the three hundredth day under his observation were females. It may be reasonably inferred that while the prevailing tendency is to carry the males overtime, yet that the smaller and comparatively much less developed female sometimes fails to stimulate the womb to contraction until very far beyond the regular date.
HYGIENE OF THE PREGNANT COW.
Among domestic animals considerations of hygiene must be made subservient to profit, and therefore the first consideration is not to obtain the most robust health, but such a measure of vigor and stamina as is compatible with the most profitable utilization of the animal. The breeding cow must carry a calf every year, and this notwithstanding that she is at the same time suckling another large, growing calf. The dairy cow must breed every year, and at the same time must furnish a generous flow of milk from nine to eleven months yearly. If her health is lowered thereby or her life shortened, the question of profit must still hold sway, and, when disqualified, she must yield her place to another. There are exceptions, of course, but this rule generally holds.
There are certain points, however, in which the interests of hygiene may be considered. The pregnant cow should have exercise, and as regards both exercise and feed, nothing is better than a run on a smooth pasture. She should be withheld from all violent excitement, hunting with dogs, riding or being ridden by cows in heat, driving in herd rapidly through narrow gateways, causing to jump ditches or fences, subjecting to blows with the horns of pugnacious cattle, driving on icy or otherwise slippery ground, carrying in railroad cars, kicking by vicious attendants, and fastening or throwing down for operations. The diet should be good, not of a kind to fatten, but with a generous quant.i.ty of nitrogenous const.i.tuents which will favor both the yield of milk and the nourishment of the fetus. Aliments like wheat bran, middlings, etc., which are rich in lime and phosphates, can be used to advantage, as there is a constant drain of earthy salts for the building of the body of the calf, and thereby the danger of undue concentration of the urine is lessened. Hard, innutritious, and indigestible aliments, musty grain or hay, partially ripened rye gra.s.s, millet, Hungarian gra.s.s, vetches, peas, or maize are objectionable, as they are liable to cause indigestion or even paralysis; and corn or hay affected by s.m.u.t or ergot, or that has been spoiled by wet, overripened, and rendered fibrous and innutritious, is equally objectionable. In the main the feed should be laxative, as costiveness and straining are liable to cause abortion. Roots and green feed that have been frosted are objectionable, as being liable to cause indigestion, though in their fresh condition most wholesome and desirable. Ice-cold water should be avoided, as calculated to check the flow of milk, to derange digestion, and to cause abortion. A good temperature for the drink of the dairy cow is 55 F.
In the case of plethoric and heavy-milking cows of mature age and in the prime of life, the hitherto liberal diet must be changed at the last week for the scantiest possible fare, and the bowels must be kept open by laxatives, if need be, if the owner would avoid milk fever. Her stall should not incline downward from shoulder to croup, lest the pressure of the abdominal organs should produce protrusion or abortion. She should be kept aloof from all causes of acute diseases, and all existing diseases should be remedied speedily and with as little excitement of the abdominal organs as possible. Strong purgatives and diuretics are to be especially avoided, unless it is in the very last days of gestation in very plethoric cows.
PROTRUSION OF THE v.a.g.i.n.a (PROLAPSUS v.a.g.i.n.ae).
During pregnancy this is common from chronic relaxation of the v.a.g.i.n.al walls and from lying in stalls that are lower behind than in front. The protrusion is of a rounded form and smooth, and if it embraces both sides of the ca.n.a.l it is double, with a pa.s.sage between. It may sometimes be remedied by raising the hind part of the stall higher than the front part.
This failing, a truss may be applied as for eversion of the womb, and worn until the period of calving approaches. (Pls. XXII, XXIII.)
HERNIA (BREACH) OF THE UTERUS.
In advanced pregnancy this occurs usually from a gradual relaxation and distention of the lower wall of the abdomen in the region of the udder, so that the latter is displaced downward, and in the sac above and in front of it may be felt the form and movements of the fetus. In other cases the womb escapes through a great laceration of the abdominal muscles to one side of the udder, and the hernial ma.s.s extends down to one side of that organ.
However unsightly, this often allows the animal to complete its pregnancy naturally, and a broad, supporting bandage placed around the abdomen is about all that can be recommended. After calving it is best to fatten the cow.
CRAMPS OF THE HIND LIMBS.
The compression of the nerves by the womb and fetus pa.s.sing through the pelvis sometimes causes cramp and inability to move the limb, but it disappears under friction and motion and is never seen after calving.
DROPSY OF THE HIND LIMBS AND BETWEEN THE THIGHS.
In the latter months of pregnancy the hind legs may swell beneath the hocks, or a soft swelling which pits on pressure with the finger appears from the v.u.l.v.a down between the thighs to the udder and in front. It is mainly ascribable to the pressure of the enlarged womb on the blood vessels, is not dangerous, and disappears after calving.
DROPSY OF THE MEMBRANES OF THE FETUS (DROPSY OF THE WOMB).
The unimpregnated womb may be filled with a dropsical fluid, but the pregnant womb is more liable to become overdistended by an excess of fluid in the inner water bag in which the fetus floats. (Pl. XII.) From an unhealthy state of this membrane or of blood of the fetus (water blood) this liquid may go on acc.u.mulating until the cow seems almost as broad as she is long. If the trouble has not originated in the ill health of the cow, the result is still to draw on her system, overtax her strength, and derange her digestion, so that the result may prove fatal to both mother and offspring. On the other hand, I have known extreme cases that came to the natural term without help and produced a living calf, after which the dam did well. The natural resort is to draw off a portion of the fluid through a hollow needle pa.s.sed through the neck of the womb or through its tense wall adjacent. This may be repeated several times, as demanded, to relieve the cow from the injurious distention.
PARALYSIS OF THE HIND PARTS.
In ill-fed, weak, unthrifty cows palsy of the hind limbs and tail may appear in the last weeks of pregnancy. The a.n.u.s and r.e.c.t.u.m may partic.i.p.ate in the palsy so far as to prevent defecation, and the r.e.c.t.u.m is more or less completely impacted. Exposure to wet and cold are often accessory causes, though the low condition, general weakness, and the pressure on the nerves going to the hind limbs are not to be forgotten. Something may be done for these cases by a warm, dry bed, an abundant diet fed warm, frictions with straw wisps or with a liniment of equal parts of oil of turpentine and sweet oil on the loins, croup, and limbs, by the daily use of ginger and gentian, by the cautious administration of strychnia (1 grain twice daily), and by sending a current of electricity daily from the loins through the various groups of muscles in the hind limbs. The case becomes increasingly hopeful after calving, though some days may still elapse before the animal can support herself upon her limbs.
EXTRAUTERINE GESTATION (FETUS DEVELOPING OUTSIDE THE WOMB).
These curious cases are rare and are usually divided into three types: (1) That in which the fetus is formed in or on the ovary (ovarian gestation); (2) that in which it is lodged in the Fallopian tube, or ca.n.a.l between the ovary and womb (tubal gestation); and (3) that in which it is lodged in the abdominal cavity and attached to one or more of its contents from which it draws its nourishment (abdominal gestation). Undoubted cases of the first and last varieties are recorded as occurring in the cow. The explanation of such cases is to be found in the fact that the actively moving sperm cells (spermatozoa) thrown into the womb have made their way through the Fallopian tubes to the ovary. If they met and impregnated an ovum in the tube, and if the consequent growth of that ovum prevented its descent and caused its imprisonment within the tube, it developed there, getting attached to and drawing nourishment from the mucous walls. Such product has its development arrested by compression by the undilatable tube, or, bursting through the walls of the tube, it escapes into the abdomen and perishes. If, on the contrary, the spermatozoa only meet and impregnate the ovum on or in the ovary, the development may take place in the substance of the ovary, from which the fetus draws its nourishment, or the impregnated ovum, escaping between the ovary and the open end of the tube, falls into the abdominal cavity and becomes adherent to and draws nourishment from some of the abdominal organs (womb, bowel, liver, stomach, etc.).
_Symptoms._--The symptoms are those of pregnancy, which may be suddenly complicated by inflammation (peritonitis), owing to rupture of the sac containing the fetus; or at full term signs of calving appear, but no progress is made; an examination with the oiled hand in the v.a.g.i.n.a or r.e.c.t.u.m finds the womb empty and its mouth closed. Further examination will disclose the fetal sac attached in some part of the abdominal cavity and containing the more or less perfectly developed body of a calf. In the most hopeful cases the fetus perishes at an early stage of gestation, becomes inclosed in a fibrous sac, and is slowly absorbed, its soft parts becoming liquefied and removed and the bones remaining encysted. In some cases the bones have finally sloughed into the r.e.c.t.u.m or through an artificial opening in the side of the belly.
_Treatment._--Little can be done in such cases except to quiet pain and excitement by anodynes (opium, chloral, etc.) and leave the rest to nature.
A fistula discharging bones may be dilated and the bones extracted, the sac being then washed out with a solution of 10 grains b.i.+.c.hlorid of mercury in a quart of water. In certain cases with a live calf a skillful operator may be justified in cutting into the abdomen and extracting the calf with its membranes, using the lotion just named as an antiseptic.
PROLONGED RETENTION OF THE FETUS.
Even when the fetus has developed within the womb it may fail to be delivered at the proper time; labor pains have quickly subsided and the cow resumed her usual health. In such cases the calf dies, and its soft parts are gradually liquefied and absorbed, while its bones remain for years in the womb inclosed in the remains of the fetal membranes. These may be expelled at any time through the natural channels, or they may remain indefinitely in the womb, not interfering with the general health, but preventing conception.
If the true condition of things is recognized at the time of the subsidence of the labor pains, the mouth of the womb may be dilated by the fingers, by the insertion of sponge tents, or by a mechanical dilator (Pl. XX, fig. 6), the fetal membranes may be ruptured and the calf extracted. After the removal of the calf and its membranes the danger of putrid poisoning may be obviated by injecting the antiseptic solution advised in the paragraph above.
ABORTION (SLINKING THE CALF).
Technically, abortion is the term used for the expulsion of the offspring before it can live out of the womb. Its expulsion before the normal time, but after it is capable of an independent existence, is premature parturition. In the cow this may be after seven and one-half months of pregnancy. Earl Spencer failed to raise any calf born before the two hundred and forty-second day. Dairymen use the term abortion for the expulsion of the product of conception at any time before the completion of the full period of a normal pregnancy, and in this sense it will be used in this article.
Abortion in cows is either contagious or noncontagious. It does not follow that the contagium is the sole cause in every case in which it is present.
We know that the organized germs (microbes) of contagion vary much in potency at different times, and that the animal system also varies in susceptibility to their attack. The germ may therefore be present in a herd without any manifest injury, its disease-producing power having for the time abated considerably, or the whole herd being in a condition of comparative insusceptibility. At other times the same germ may have become so virulent that almost all pregnant cows succ.u.mb to its force, or the herd may have been subjected to other causes of abortion which, though of themselves powerless to actually cause abortion, may yet so predispose the animals that even the weaker germ will operate with destructive effect. In dealing with this disease, therefore, it is the part of wisdom not to rest satisfied with the discovery and removal of one specific cause, but rather to try to find every existent cause and to obtain a remedy by correcting all the harmful conditions.
NONCONTAGIOUS ABORTION.