unexpectedly, strain the loins and jar the body and womb most injuriously.
Slippery stalls in which the flooring boards are laid longitudinally in
place of transversely, and on which there is no device to give a firm
foothold, are almost equally dangerous. Driving on icy ground, or through a
narrow doorway where the abdomen is liable to be jammed, are other common
causes. Aborting cows often fail to expel the afterbirth, and if this
remains hanging in a putrid condition it is most injurious to pregnant cows
in the near vicinity. So with retained afterbirth in other cows after
calving. That some cows kept in filthy stables or with slaughterhouses near
by may become inured to the odors and escape the evil results is no
disproof of the injurious effects so often seen in such cases.
The excitement, jarring, and jolting of a railroad journey often cause
abortion, especially as the cow nears the period of calving, and the terror
or injury of railway or other accidents proves incomparably worse.
All irritant poisons cause abortions by the disorder and inflammation of
the digestive organs, and if such agents act also on the kidneys or womb,
the effect is materially enhanced. Powerful purgatives or diuretics should
never be administered to the pregnant cow.
Among other causes of abortion must be named the death or the various
illnesses of the fetus, which are about as numerous as those of the adult;
the slipping of a young fetus through a loop in the navel string so as to
tie a knot which will tighten later and interrupt the flow of blood with
fatal effect, and the twisting of the navel string by the turning of the
fetus until little or no blood can flow through the contorted cord. There
is in addition a series of diseases of the mucous membrane of the womb, and
of the fetal membranes (inflammation, effusion of blood, detachment of the
membranes from the womb, fatty or other degenerations, etc.), which
interfere with the supply of blood to the fetus or change its quality so
that death is the natural result, followed by abortion.
_Treatment._--Although the first symptoms of abortion have appeared, it
does not follow that it will go on to completion. So long as the fetus has
not perished, if the waters have not been discharged, nor the water bags
presented, attempts should be made to check its progress. Every appreciable
and removable cause should be done away with, the cow should be placed in a
quiet stall alone, and agents given to check the excitement of the labor
pains. Laudanum in doses of 1 ounce for a small cow or 2 ounces for a large
one should be promptly administered, and repeated in three or four hours
should the labor pains recur. This may be kept up for days or even weeks if
necessary, though that is rarely required, as the trouble either subsides
or abortion occurs. If the laudanum seems to lack permanency of action, use
bromid of potassium, or, better, extract of _Viburnum prunifolium_ (black
haw), 40 grains, at intervals of two or three hours until five or six doses
have been given.
CONTAGIOUS ABORTION.
Contagious abortion (also known as epizootic abortion, enzootic abortion,
and slinking of calves) is a disease affecting chiefly cattle and to a
lesser degree other domestic animals, and characterized by an inflammatory
condition of the female reproductive organs, which results in the expulsion
of the immature young.
_History._--This disease has been known in England and continental Europe
for many years, and descriptions of it are mentioned in the writings of
Mascal, Lafoose, Skellet, Lawrence, St. Cyr, Z¸ndel, and Youatt. In the
early part of the eighteenth century British veterinarians recognized its
contagiousness, but it remained for Franck (1876), Lehnert (1878), and
Br‰uer (1880) to produce the disease in healthy, pregnant cows by the
introduction of exudate and material from aborting animals. Nocard (1888)
isolated from the exudate between the mucous membrane of the uterus and
fetal membranes a micrococcus and a short bacillus which were found
continually in contagious abortion, but he failed to reproduce the disease
by inoculations of pure cultures of these organisms into healthy, pregnant
animals. In 1897 Bang, assisted by Stribolt, published their findings
regarding infectious abortion of cattle, in which they incriminated Bang's
bacillus of abortion as the causative agent. With pure cultures of this
bacillus they were able to produce the disease artificially and to recover
the same organism from the experimental cases. Since that time many noted
investigators, both in this country and in Europe, have confirmed these
findings.
_Cause._--The _Bacterium abortus_ of Bang is now generally recognized as
the causative agent of the disease of cattle. Formerly it was thought that
abortion was due to injury, such as blows, horn thrusts, falls, etc., or
the eating of spoiled feed and certain plants, and while this may be true
in a limited number of cases, careful investigations have demonstrated
these claims to be largely unfounded. It is now generally recognized that
when abortion occurs in herds from time to time, it is safe to assume that
the disorder is of an infectious nature and should be so treated.
_Natural mode of infection._--This phase of the disease is of greatest
importance for a clear understanding of the methods of prevention. Many
investigators have demonstrated that the infection is transmitted through
the digestive tract, through contaminated feed and water. The germs are
taken up by the body from the intestines with the liquid nourishment, reach
the blood, and are carried to the genital organs, where they find
conditions best suited to their development. Some assert that calves are
infected in this manner by suckling infected mothers, the germs being
present in the milk, or the teats having been contaminated by coming in
contact with infective discharges. It is claimed that infection contracted
in this manner remains dormant in the body of the calf until pregnancy
begins, and then the organism, finding conditions suitable for its
development, produces the disease.
Abortion may occasionally be transmitted from cow to cow by direct contact.
The discharges from diseased cows, swarming with the germs, soil the
external genitals, tail, and hind quarters, and then a susceptible animal,
by contact, gets the infective material upon the vulva, the infection
traveling up the genital canal and directly infecting the uterus.
The belief long entertained that the female acquires the disease at the
time of copulation as a result of transference of the infection from
affected to healthy females on the genital organs of the bull has failed to
receive the support of experimental evidence. The view that the disease is
spread to any great degree in this way has been largely discredited. Cows
of all ages are more or less susceptible, but young ones in first or second
pregnancy most frequently abort. A second abortion is not unusual, and a
third may occasionally occur, after which the cow usually becomes immune
and thereafter carries her calf to maturity. Heifers from aborting mothers
sometimes seem to be less susceptible than others.
_Symptoms._--Contagious abortion is a very insidious disease, developing
very slowly through several months of the gestation period, and resulting
finally in the expulsion of the immature young, this act being simply an
indication of the presence of the disease and not the disease itself.
Because of this slow development and the fact that the health of the animal
is not noticeably influenced, the presence of the disease may not be
suspected until it has gained a firm foothold in the herd. The symptoms of
approaching abortion are those preceding normal calving. In addition, there
may be observed, a few days previous to abortion, a sticky, sometimes
purulent, rusty, and odorless discharge. Abortion occurs most frequently
from the third to the seventh month, according to the number of abortions,
occurring early in first abortion, and later in each succeeding abortion
until the calf is carried to full term and the mother has become immune. It
happens frequently that calves are carried almost to full term, and are
born alive, but are sickly, and soon die. Following abortion there is a
dirty, yellowish-gray mucopurulent discharge which persists for two or more
weeks. If abortion occurs early, the fetus is passed surrounded by its
membranes, but if late in the period of pregnancy, the membranes are
retained, decomposition sets in and blood poisoning, which may cause the
death of the animal, or sterility may result.
_Lesions._--The most characteristic change is found in the uterus where a
dark-brown fluid, purulent or even gluey in consistency, and containing
grayish-white flakes separates the material membranes from those of the
fetus, preventing that intimate contact between the two which is so
necessary for the interchange of fluids and gases by which the fetus is
nourished and by which it obtains its oxygen. These being cut off, the
fetus must of course die. The germs producing the disease are found in
greatest numbers at this point. In addition there may be inflammatory
changes, first in the walls of the uterus and then in the tissues of the
fetus. These inflammatory changes seem most intense in the cotyledons and
result in the destruction of the minute structure of those bodies, and they
appear swollen, pale, and soft. The membrane of the uterus between the
cotyledons also may show inflamed and necrotic patches.
_Complications._--Serious results sometimes follow abortion, and this is
particularly the case when there is retained afterbirth. The retained
membranes decompose, the poisonous products of decomposition and the
organisms of decomposition themselves are absorbed, blood poisoning
results, and the animal dies. Sometimes, when the animal is able to resist
the effects of this decomposition, the uterus becomes the seat of such
severe changes that sterility results. The walls of that organ become
thickened and hard, the lining membranes become eroded, and conception can
not take place. At other times the ovaries, where the reproductive cells
originate, become affected and lose their function. Abortion does not
invariably follow infection, but the calf is carried to full term. In these
cases, however, retained afterbirth is a common occurrence, even to the
extent that frequent retention of afterbirth in a herd may be taken as an
indication of the presence of the disease. Very often suppurative processes
persist for a long time, preventing conception, or sterility may result
without apparent cause. A sterile cow is valueless, of course, for any
purpose except for beef. Such animals are a source of infection for the
others and should not be allowed to remain in the herd.
_Diagnosis._--The diagnosis of infectious abortion is made from the changes
occurring in the fetal membranes and in the expelled fetus. This, however,
is substantiated with certainty only by microscopic demonstration of the
germ of abortion. The fact that repeated abortions are observed in a herd
is also evidence of the presence of the disease. In consideration, however,
of the fact that animals may be affected with the disease and disseminate
the germs, even though they carry the fetus to full time, a diagnosis in
such instances is only possible by laboratory methods. For this purpose the
agglutination and also the complement-fixation tests are being used with
splendid results, and by the aid of these biological tests it is possible
to determine all infected animals in a herd. The tests are carried out with
the serum from animals to be examined, only a teaspoonful of serum being
necessary for the execution of both of these tests. It, however, has to be
confined to laboratories which are properly equipped for such work.
_Treatment and prevention._--It may be said in general that treatment is
without avail and all efforts should be directed toward prevention. Various
medicinal agents, such as carbolic acid administered subcutaneously and
methylene blue fed in large quantities, have been recommended, but have
failed to stand the tests of scientific investigation and practical use.
Serums and vaccines have also been prepared and sold as cures and
preventives, but the work is still considered in the experimental stage.
Bacterial vaccines are at present extensively used in the control of this
disease, and while numerous reports indicate beneficial results from their
administration, in other instances total failures have been recorded. It
appears that the experiments in this line have not progressed sufficiently
to justify definite conclusions.
The spread of the disease can be controlled to a great degree by the
practice of sanitary measures directed toward the disinfection of premises
and the isolation of animals at time of calving and aborting. For methods
of disinfection of premises see page 363.
Make frequent observations of the animals of affected herds for symptoms of
aborting, such as swelling of vulva or udder enlargement, and upon the
discovery of an animal showing these symptoms place her immediately in a
stall which is somewhat remote from healthy stock as a means of confining
the products of abortion as much as possible should the act occur. If an
animal aborts unexpectedly she should be removed to separate quarters and
given proper attention as promptly as possible. The fetus, afterbirth,
provided it has been expelled, and all litter that has been contaminated
with them and uterine discharges should be gathered up and destroyed either
by burning or burying. Clean and thoroughly disinfect the floor, gutters,
and manger in the vicinity of the aborting animal.
Daily irrigations of the uterus with nonirritating antiseptic solutions,
such as 0.5 per cent solution of cresol or compound solution of cresol, at
body temperature have a tendency to prevent the multiplication of
microorganisms in the uterus and in this way promote recovery. Douching of
the uterus should be continued until the discharge ceases. In addition, the
external genitals, root of the tail, escutcheon, etc., should be sponged
daily with the antiseptic solution.
Aim to place all pregnant animals in disinfected individual pens or stalls
a few days before they are expected to calve, and confine them to these
quarters for three or four weeks following the delivery of the calf, or as
long thereafter as uterine discharges are observed. Avoid carrying
infection from the maternity stalls to other portions of stable, on shoes
or otherwise. This may be prevented to some degree by the use of
disinfectant solutions on shoes after the stalls have been entered or by
wearing rubbers while in the maternity stalls, removing them after the
isolated animals have been attended to. The isolation of cows at time of
calving and the aborting animal is based upon the knowledge that the fetus,
afterbirth, and uterine discharges of an affected animal at these times
very frequently contain myriads of the abortion bacteria, and that unless
these substances are confined and promptly destroyed an abundant
opportunity is provided for the contamination of the food substances of the
healthy animals and their contraction of the disease.
Refrain from breeding fresh cows for a period of six weeks to two months
following calving. The aborting animal should be isolated for a period of
six weeks to two months and under no consideration be permitted to mingle
with the rest of the herd as long as uterine discharges are observed.
Douching of the external genitals of the bull, a practice formerly regarded
as highly important for preventing the spread of the disease, is now
recognized as being of doubtful value. The bull is protected from abortion
infection to a great degree by permitting him to serve only such animals as
have calved or aborted from six weeks to two months previously.
Investigational work has indicated that when the bull is affected with the
disease the organs of his generative system commonly involved are not
reached by the antiseptic solutions. A more rational method for the
prevention of the spread of the disease by the bull consists in keeping him
in an inclosure separate from the females and in having all services take
place on neutral ground.
Great care should be used in purchasing cattle, and cows not known to be
free from the disease should be kept in separate quarters until this point
is determined.
GRANULAR VENEREAL DISEASE (INFECTIOUS GRANULAR VAGINITIS).
The affection to which the foregoing names have been given is a chronic,
mild, and apparently contagious disease of cattle, characterized by an
inflammatory condition of the mucous membrane of the vagina and the
development of nodules upon its surface.
This disease is very widely spread, but from an economic point of view it
does not appear to have great significance. Williams, who investigated it,
asserts that it is difficult to find a single herd in this country which is
free of this disease. He considers it of great importance, claiming that
granular vaginitis has a vital relation to abortion. This view, however, is
not substantiated by other investigators, it being now generally accepted
that the disease is only rarely responsible for abortion, and further, that
it exerts no apparent ill effects on the health of the animal and that it
has no effect on the milk yield.
_Symptoms._--Natural infection may take place either by direct contact of
animals or at the time of service. Most of the cows in the affected herd
contract the disease, but the bulls are rarely or very mildly affected. The
inflamed condition of the membranes of the vagina results in a catarrhal
exudate, and this discharge, which soils the external genitals and the
tail, and the uneasiness and sometimes the straining of the animal, are the
first and most prominent symptoms observed. Upon examination, small, hard,
grayish nodules can be seen and felt upon the inflamed membranes. This
acute stage may last for three or four weeks, then it gradually subsides
and assumes the chronic form, only to flare up again as the animal comes in
heat.
These nodules are sometimes found on the membranes of the uterus, and some
investigators have argued from this fact that it was responsible for
abortion and sterility. Others, however, deny this and point out that the
bacillus of abortion can be demonstrated in nearly every case. The
importance of the disease is therefore in dispute and the decision must be
left to future investigation.
_Treatment._--The exaggerated importance which has been attached to this
disease resulted in the exploitation of the most varied kinds of remedies
for its treatment. It is true that with a protracted and laborious
treatment it is possible to effect cures in from one to three months, but
with our present knowledge of this disorder it is advisable to limit the
treatment to animals which show an acute inflammatory condition of the
vagina and vulva with a discharge as a result of the granular affection.
The treatment should be local and confined to the application of antiseptic
washes in the form of irrigations. For this purpose a 0.5 per cent solution
of the compound solution of cresol or of Lugol's solution has been found
satisfactory.
PARTURITION (CALVING).
SYMPTOMS OF CALVING.
In the cow the premonitions of calving are the enlargement of the udder,
which becomes firm and resistant to the touch, with more or less swelling
in front, and yields a serous, milky fluid; the enlargement and swelling of
the vulva, which discharges an abundant, stringy mucus; the drooping of the
belly, and the falling in of the muscles at each side of the root of the
tail, so as to leave deep hollows. When this last symptom is seen, calving
may be counted on in 24 hours or in 2 or 3 days. When the act is imminent,
the cow becomes uneasy, moves restlessly, leaves off eating, in the field
leaves the herd, lies down and rises again as if in pain, shifts upon her
hind feet, moves the tail, and may bellow or moan. When labor pains come on
the back is arched, the croup drooped, the belly is drawn up, and straining
is more or less violent and continuous. Meanwhile blood may have appeared
on the vulva and tail, and soon the clear water bags protrude between the
lips of the vulva. They increase rapidly, hanging down toward the hocks,
and the fore or hind feet can be detected within them. With the rupture of
the bags and escape of the waters the womb contracts on the solid, angular
body of the fetus and is at once stimulated to more violent contractions,
so that the work proceeds with redoubled energy to the complete expulsion.
This is why it is wrong to rupture the water bags if the presentation is
normal, as they furnish a soft, uniform pressure for the preliminary
dilation of the mouth of the womb and passages, in anticipation of the
severe strain put upon them as the solid body of the calf passes.
The cow often calves standing, in which case the navel string is broken as
the calf falls to the ground. If, however, she is recumbent, this cord is
torn through as she rises. The afterpains come on 3 or 4 hours later and
expel the membranes, which should never be left longer than 24 hours.
NATURAL PRESENTATION.
When there is but one calf the natural presentation is that of the fore
feet with the front of the hoofs and knees turned upward toward the tail of
the dam and the nose lying between the knees. (Pl. XV.) If there are twins
the natural position of the second is that of the hind feet, the heels and
hocks turned upward toward the cow's tail. (Pl. XVIII, fig. 1.) In both of
these natural positions the curvature of the body of the calf--the back
arched upward--is the same with the curvature of the passages, which
descend anteriorly into the womb, ascend over the brim of the pelvis, and
descend again toward the external opening (vulva). Any presentation
differing from the above is abnormal.
OBSTACLES TO PARTURITION.
With a well-formed cow and calf and a natural presentation as above,
calving is usually prompt and easy. Obstacles may, however, come from
failure of the mouth of the womb to dilate; from twisting of the neck of
the womb; from tumors in the vagina; from dropsy in the womb or abdomen;
from overdistention of the rectum or bladder; from undue narrowing of the
passages; from excess of fat in the walls of the pelvis; from the
disturbance of a nervous cow by noises; from stone or urine in the bladder;
from wrong presentation of the calf, its back being turned downward or to
one side in place of upward toward the spine of the dam; from the bending
backward of one or more limbs or of the head into the body of the womb;
from presentation of the back, shoulder, or croup, all four limbs being
turned back; from presentation of all four feet at once; from obstruction
caused by an extra head or extra limbs, or double body on the part of the
offspring (Pl. XIX); from dropsy or other disease of the calf; from
excessive or imperfect development of the calf; from the impaction of twins
into the passages at the same time; or at times it may be from the mere
excessive volume of the fetus.
GENERAL MAXIMS FOR THE ASSISTANT CONCERNING DIFFICULT PARTURITION.