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HARVARD -UNIVERSIDY:
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MUSEUM OF COMPARATIVE ZOOLOGY.
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Oclobev. 3. 1917.
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LIBRARY
HOG CHOLERA i100
PREVENTION AND TREATMENT
M. DORSET
Chief of the Biochemic Division
and
O. B. HESS
In Charge of Office of Hog-Cholera Control
The two pigs shown in foreground are affected with hog cholera
FARMERS’ BULLETIN 834
UNITED STATES DEPARTMENT OF AGRICULTURE
Contribution from the Bureau of Animal Industry
A. D. MELVIN, Chief
j Washington, D. C. August, 1917
Show this bulletin to a neighbor. Additional copies may be obtained free from the
Division of Publications, United States Department of Agriculture
WASHINGTON : GOVERNMENT PRINTING OFFICE 2 1917
OG CHOLERA destroys about 90 per cent of all hogs that
die from disease in the United States. The losses have
amounted to between 6,000,000 and 7,000,000 hogs in one
year, and the money loss probably has averaged more than
$30,000,000 a year for the last 40 years.
The Federal Government and the State authorities aim at the
ultimate eradication of the disease. At present the object is
to bring it under strict control so as to reduce losses to the
minimum.
Cooperation by farmers with each other and with the Federal
Government and State authorities is essential to success.
The infection is carried easily from one place to another in
a great variety of ways. Hence the need of care and coopera-
tion by all concerned.
Sanitation, disinfection, and a self-imposed quarantine are
important when the disease is in the neighborhood.
Prevention is better than cure. In fact there is no specific
cure. So-called hog-cholera medicines are a snare and a delu-
sion. The Bureau of Animal Industry for many years has made
a study of the disease and finally evolved the “ anti-hog-cholera
serum,” which can be regarded as the only known reliable pre-
ventive agent. It is the only agent which has been proved to
have curative properties. This serum is now manufactured by
several State institutions and by private firms licensed by the
Secretary of Agriculture for the purpose. The use of the serum
is described fully herein, including treatment of herds, brood
sows, young pigs, etc.
Confine sick hogs.
Use serum.
Employ sanitary measures.
Disinfect.
Cooperate.
HOG CHOLERA: PREVENTION AND
TREATMENT.
CONTENTS.
Page Page
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PREVENTION AND TREATMENT.
HOG CHOLERA
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HOG OVALLAPA STATISTICS.
FIGURES NOT UNDERSCORED STOW
WOMEER OF HOGS SAN. 1, 5H.
FIGURES UNDERSCORED SHOW LOSSES
FOR YEAR ENOING MARCYT 3, (WA.
Fic. 1.—KEstimated number of hogs on hand Jan. 1, 1914, and losses from hog
cholera for year ending March 381, 1914.
At times the value of hogs destroyed by cholera in the United
States has amounted to about $65,000,000 in a single year, and the
average annual loss for the last 40 years probably has not been less
than $30,000,000. This represents merely the direct losses; if the in-
direct losses could be computed these figures would be increased
greatly. Figure 1 shows for each State the estimated number of hogs
on hand January 1, 1914, and the estimated losses from cholera
during the year ending March 31, 1914. Table 1 gives similar infor-
mation for the years 1913 to 1917, inclusive.
The losses from hog cholera in the United States during the last
24 years are shown in figure 2. It will be noted that the decline
since 1914 has been quite rapid.
THE CAUSE OF HOG CHOLERA.
Hog cholera is a highly contagious disease of swine, caused by a
germ or microorganism which is present in the blood, urine, feces,
and the eye and nose secretions. It is accompanied by fever, has a
high death rate, and, so far as known, does not affect other animals
or man.
The germ has never been cultivated artificially in laboratories, as
many other infectious germs have. It can not be seen, even with the
most powerful microscopes; it passes readily through the pores of
the finest filters, which will hold back all visible bacteria; and it is
known only by the effects which it produces. In these respects it
resembles the germs that cause foot-and-mouth disease in cattle and
yellow fever in man. Although insanitary surroundings and im-
HOG CHOLERA: PREVENTION AND TREATMENT, a
proper feeding tend to lower vitality and thus perhaps render ani-
mals more susceptible to disease, such conditions can not of them-
selves cause hog cholera. It can be produced only by the specific
microorganism referred to.
SYMPTOMS SHOWN BY HOGS SICK WITH CHOLERA.
The symptoms of hog cholera differ in different hogs and in differ-
ent herds, depending upon the strength of the germs and the resist-
ing power of the hogs. As a result of these variations the disease
has been said to exist in two forms, acute and chronic, though the
germ is the same in both. In the acute or severe type hogs sicken
and die quickly, so that farmers will say that a hog which is found
_ dead in the morning was well the night before. In the chronic or
less severe type hogs may be sick for weeks or months before they
succumb.
When cholera begins in a herd the hogs do not all become sick
at once, but on the contrary only one or two will refuse to come up to
feed with the herd. They will remain hidden in the nest (fig. 3)
and when driven from the bed their backs may be arched and they
may appear cold and shiver. The balance of the herd may remain
pugpnagas
YOGONRHAOALVHYOON
BUSSE ETT I TG 8
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OE Le) 2 (I A a SD
USAR LOSSES PER /OOO
oe SU? SIO0CS 1 PROTA IOC OAOLLAA
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Fig. 2.—Losses frem hog cholera in the United States, 1894-1917, inclusive.
PP SSe kheeeane
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8 FARMERS’ BULLETIN 834,
apparently well for several days, when others are likely to be found
affected in about the same way as those first attacked. As the disease
progresses the sick hogs become gaunt or tucked up in the flank, and
have a weak, staggering gait, the weakness being most marked in the
hind legs.
If the lungs are affected there may be a cough, which is particularly
noticeable ‘when the hogs are disturbed. The eyes usually are in-
flamed and show a whitish discharge, which may cause the lids to
stick together.
Constipation, which is commonly present in the early days of the
disease, is generally followed by a diarrhea. As the disease reaches
its height, red or purplish blotches are likely to appear upon the skin
of the ears, of the belly, and of the inner surfaces of the legs.
Some of the symptoms mentioned may be present in other diseases,
but the owner should remember that cholera spreads rapidly through
a herd (fig. 4) and too much time should not be lost in undertaking
to distinguish it from some other disease.
The temperature of the hogs is of much importance in diagnosing
cholera. The normal temperature in ordinary weather when the
hogs are not excited or worried will range from 101° to 104° F., but
when cholera is present it is not uncommon to find a large proportion
of the hogs with temperatures from 104° to 107°, and even higher.
Fic. 3.—First indications of cholera; two pigs remaining in nest.
00 0!!0=0QnNVCOCO — —— a ———<— —
HOG CHOLERA: PREVENTION AND TREATMENT. 9/
Fic. 4.—A herd affected with acute cholera in which practically every hog is sick.
APPEARANCE OF A HOG AFTER DEATH FROM CHOLERA.
Examination of carcasses of hogs that die will assist in determin-
ing whether they have died of cholera. In making an examination
after death the skin should first be examined for purple blotches
resembling a birth mark. Then the carcass should be placed on its
back and opened in the same manner as when butchering for mar-
ket, care being taken to avoid cutting the internal organs.
Lungs.—In acute cholera the surfaces of the lungs frequently show
small red spots varying in size from a pinhead to a small pea. These
spots can not be washed off, and when found are an important indi-
cation of cholera. It is not unusual, instead of finding the lungs
soft, filled with air, and pinkish in color, as is the case in a nornial
condition, to find them solid and of a grayish or dark-red color,
which results from a form of pneumonia. This condition, however,
is not so characteristic of hog cholera as the reddish spots mentioned.
Heart—When removed from the membranous sac surrounding it,
the heart may show blotches or blood spots such as those on the
lungs. These, however, are seen only in rare cases in the acute or
severe form of hog cholera.
Liver—The liver generally shows changes, but it varies in ap-
pearance even under normal conditions, and, therefore, does not
show changes that can be regarded as characteristic of cholera.
Spleen or melt——tIn acute cases of hog cholera the spleen or melt
is invariably large, dark, and soft. In chronic cases, however, it
may be smaller than normal and grayish in color.
Kidneys——The kidneys when removed are found surrounded by
a thin, fibrous tissue. This should be peeled off carefully to avoid
98028 °—Bull. 884172
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10 FARMERS’ BULLETIN 834.
injury to the surface of the kidney and an examination made for
dark-red spots varying in size from mere points to areas as large as
the head of a pin. These spots may be
few, or the surface of the kidney may
be as speckled as a turkey’s egg.
These spots on the kidneys when well
marked are regarded generally as one.
of the surest signs of hog cholera
(fig. 5).
Bladder.—The inner surface of the
bladder under normal conditions is
white or a faint pinkish-white in
color, but in well-marked cases of hog
cholera it may show bright red specks
which can not be washed off. In cases
of long standing there may be ulcers.
Stomach.—In some cases of hog
cholera, when the stomach is opened
and washed out, red spots and ulcera-
tions may be found on the inner
lining.
Small intestines —In some acute
and virulent types of hog cholera the
outer surface of the small intestines
may have the appearance of being spat-
tered with blood. The bloody spots,
however, can not be removed by wash-
ing. The inner lining may be congested, inflamed, greatly thickened,
and covered with a yellowish coating; or it may be dotted with
small blood spots, like those seen on the outer surface.
Large intestines.—The large intestine may show, over the outer
surface, the same characteristic blood spots as are seen at times on
the small intestines. The inner lining in acute cases of hog cholera
also may show small blood-stained areas, and in addition to this the
feces found in this portion of the bowel may be covered with blood
In chronic cases, where the hog has been sick for some time, there
are usually found on the inner surface of the large intestine round,
hard areas called “ button ulcers.” These ulcers are raised above the
surrounding tissue and usually are yellowish in color, while the
larger ones may have a dark center. These ulcers vary in size from
one-sixteenth of an inch to 1 inch in diameter, and are not found in
any other disease of swine (fig. 6).
Lymphatic glands.—The changes which take place in the lymphatic
glands as a result of hog cholera frequently are striking. The most
important glands to be examined are found in the fat just under
Fig. 5.—Hog’s kidney, showing blood
spots caused by cholera.
HOG CHOLERA: PREVENTION AND TREATMENT. IDE
the skin of the belly, in the region of the flanks. In health these
glands are of a rather light-grayish color; in cases of cholera they
may be enlarged and red, and in severe cases they may appear almost
black. If cut through with a knife it will be found generally that
the outer portion or rind of the gland is affected to the greatest
extent. Other lymphatic glands which undergo similar changes are
found in the fatty tissues at the angle of the lower jaw and in the
thin membrane which holds the intestines together.
SUMMARY OF POST-MORTEM APPEARANCE.
To recapitulate, the important changes found in the carcass after
death from hog cholera are as follows:
1. Purple blotches on the skin.
2. Blood-colored spots on the lungs, on the surface of the heart, on the
kidneys, and on the outer surface and inner lining of the intestines and the
stomach.
3. Reddening of the lymphatic glands.
4. Enlargement of the spleen, in acute cases.
5. Ulceration of the inner lining of the large intestine.
e
Any one or all of these changes may be found in a hog which has
died from hog cholera. It is rare to find all in any one case. In the
lingering or chronic cases of hog cholera it is usual to find the intes-
tinal buttonlike ulcers, while the blood-colored spots described above
are, as a rule, found only in the acute cases.
Fic. 6.—Intestine of cholera hog, showing ulcers. (After Hutyra and Marek.)
12 FARMERS’ BULLETIN 834.
DISEASES WHICH MAY BE MISTAKEN FOR HOG CHOLERA.
A few diseases of hogs at times may be mistaken for hog cholera.
These are swine plague, tuberculosis, anthrax, necrobacillosis, and
lung and bowel disturbances due to worms.
Swine plague or pig pnewmonia.—\t is not practicable for the
farmer to attempt to distinguish between hog cholera and swine
plague, for they are so much alike that even skilled veterinarians
may find it almost impossible to distinguish one from the other.
Inasmuch as swine plague is rarely found to exist as a separate dis-
ease, and usually exists merely as a complication of hog cholera, it
is best for the farmer to treat suspected swine plague just as he
would a case of cholera.
Tuberculosis —The features which distinguish hog cholera from
tuberculosis are the facts that in the case of tuberculosis the onset is
slow rather than sudden, as in hog cholera; and that the progress of
the disease likewise is slow, it being extremely rare for hogs to die
quickly from tuberculosis. It is very possible, of course, for a whole
herd to show signs of tuberculosis at about the same time because of
having contracted the disease from the same source and at the same
time, as through feeding on tuberculous skim milk or following cattle
infected with tuberculosis.
In tuberculosis the changes which may be found in the organs after
death consist of whitish or grayish consolidated areas in the lungs,
with sometimes a yellowish, cheeselike center. Similar areas, though
not so largé, may be found in the liver, and in the spleen or melt may
be found nodules of varying size, some as large as an acorn. These
nodules project above the surface, are light-colored, and when cut
are found to consist of a tough, fibrous material which at times may
have a cheesy or granular substance in the center. The appearance
of the spleen is entirely different from that found in hog cholera.
The kidneys do not show the small dark spots that are observed in
hog cholera, and as a rule are not changed from their normal condi-
tion. Tuberculosis frequently affects the lymphatic glands, but these
changes can hardly be mistaken for lesions of hog cholera, for, unlike
cholera, tuberculosis causes the inner portion of the gland to break
down into a yellow, cheesy mass which in the advanced stage of the
disease may contain small, hard, gritty particles, resembling grains
of sand.
Anthrax—Hogs rarely are affected with anthrax, but when this
disease does occur it might readily be mistaken for the acute type of
hog cholera. The distinguishing features of anthrax in hogs are the
marked swelling of the throat and tongue, with frequently a bloody
froth in the mouth. Anthrax in hogs usually follows the disease in
-
HOG CHOLERA: PREVENTION AND TREATMENT. 13
other animals on the farm; cattle, sheep, and horses being more
susceptible than hogs. ;
Necrobacillosis—This disease may appear in various forms. One
is a condition commonly called “ sniffles” or “bull nose.’ Another
and most important form is called necrotic enteritis. The latter is
characterized by a severe inflammation of the intestines, and at times
may be mistaken for cholera. Often there is a lack of appetite,
and while diarrhea is not constant it frequently is seen in the
early stage of this disease. The pigs become unthrifty, emaciated,
and weak. The lesions of the disease are found most commonly in
the inner lining of the large intestines, but in advanced cases the
lining of the small intestines also is involved. Small, white, well-
defined areas may be seen through the outer covering of the large
intestines. On splitting open the intestine, the inner lining is found
thickened, with white, dead patches ready to slough off, but they are
not raised above the surface and do not form the buttonlike ulcers
as in chronic cholera. These patches consist of a rather soft cheesy
substance. In advanced cases the whole inner lining of the intestine
can be scraped away with the thumb nail. Under these conditions the
animal rapidly wastes away and dies from lack of nutrition. The
absence of red spots on the belly, the lack of fever, the slow develop-
ment of the disease in the herd, and the fact that it is confined prin-
cipally to pigs and shoats, all serve to distinguish this disease from
cholera.
Worms.—Growing pigs often suffer from attacks of worms, both
in the lungs and in the intestines, but old hogs rarely show the
effect of such infestation. The most important symptom produced
by worms is general unthriftiness.
The worms that infest the lungs are very small, one-half to 1 inch
in length, and they bring about an inflammation of the air passages
which causes frequent coughing. They can be recognized by a
careful examination of the frothy discharge from the mouth of
sick pigs or of the lungs after death. In this disease there is an
entire absence of symptoms of acute illness, such as usually accom-
panies an attack of hog cholera.
Worms infesting the intestines vary in size, some attaining a
length of 10 inches. These parasites impair the general health
of the pigs and by causing irritation of the alimentary tract may
cause diarrhea. While several pigs and shoats in a herd may be-
come affected with worms and act in somewhat the same way as
those attacked by hog cholera, the facts that there is no fever and
that the ailment does not affect grown hogs make this trouble easily
distinguishable from hog cholera.
14 FARMERS’ BULLETIN 834.
MODES OF INFECTION WITH HOG CHOLERA.
Hog cholera does not occur in a herd except through the intro-
duction of the specific germ of that disease. So far as known,
the germs of hog cholera develop and propagate only in the bodies
of hogs. There is no more certain way of introducing hog cholera
than by placing in the herd a hog already infected with the disease.
The sick hog, then, must be regarded as the most dangerous agent
in the spread of cholera. Hogs affected with cholera discharge the
germs of the disease from their bodies in the urine, the feces, and the
secretions of the nose and eyes. Therefore the manure, bedding,
litter of all sorts, and the dirt itself in pens where sick hogs are kept
contain the germs of the disease. These germs may enter the hog’s
system by means of food or drink and probably also through wounds
or abrasion of the skin.
The extensive shipment of hogs to market by rail has resulted in
the germs of cholera being deposited in public stockyards, in
unloading chutes and pens, and in the railroad cars used for hauling
hogs. Consequently if healthy hogs are shipped in ordinary stock
cars, or if they are unloaded in public stockyards or through public
chutes they are likely to become infected with cholera. Similarly,
it is believed that any agency which will serve to carry litter, manure,
or material of any sort from public stockyards or cars to farms may
result in an outbreak of cholera on the farm. Such infected material
may adhere to the feet of horses or other stock, to wagon wheels, or
to the shoes of men who have entered these public places.
What is true of public stockyards and stock cars is true to an
even greater extent of farms where cholera exists, and it may be
expected that the disease will be carried from an infected farm to
healthy herds if care is not taken to prevent the carrying of the
germs on the feet of men or animals, on wagon wheels, or perhaps
even by dogs roaming from one farm to another. Streams passing
through infected farms may wash the germs down to other farms
perhaps miles away. If the carcasses of dead animals have not been
disposed of promptly, dogs may carry portions to neighboring farms.
It is generally believed that buzzards and crows may carry the germs .
of cholera to clean farms. At certain seasons it is common for
farmers to exchange labor and farm implements when thrashing,
shelling corn, filling silos, and delivering grain or stock to market.
Unless proper precautions are taken it can be seen that these prac-
tices may serve to disseminate cholera. It has been said that cholera
has been traced in some instances to the visits of stock buyers and
vendors of stock remedies who go from farm to farm and from hog
lot to hog lot. If hogs on a clean farm are not kept in lots properly ©
fenced they may range to contaminated streams or to adjoining
HOG CHOLERA: PREVENTION AND TREATMENT. 15
herds and thus contract and spread cholera. It is undoubtedly true
that infection in many cases results from the purchase of new stock,
and at times from the borrowing and lending of stock for breeding
purposes. There is a record of six different farms having become in-
fected from the purchase of stock from one public sale where sick
hogs were kept hidden from view. A number of outbreaks have been
caused by the failure to take proper precautions in the case of stal-
lions and other breeding animals which were kept on infected
premises from which infection was carried through the community
from farm to farm.
Farms on which hog cholera has occurred may remain infected
for a considerable time, and a second outbreak may occur as a result
of this infection.
KEEPING CHOLERA OFF THE FARM BY SANITATION.
From what has been said it will be seen that hog cholera may be
spread in many ways, and that most, if not all, of the sources of
danger may be excluded by the use of proper care and foresight on
the part of the farmer.
With the object of assisting the farmer to protect himself the fol-
lowing suggestions are offered: Hog houses, lots, and pastures should
be located away from streams and public highways, and the houses
and lots should be arranged so that they may be cleaned and dis-
infected readily. They should be exposed as far as possible to sun-
light, which is the cheapest and one of the best disinfectants. Hog
lots should not be used for yarding wagons and farm implements
and should not be entered with team and wagon, particularly when
loading stock for shipment to market and when returning from stock-
yards and public highways. No one should be allowed to enter hog
lots unless there is assurance that he does not carry infection. Farm-
ers and their help should disinfect ' their shoes before entering hog
lots after returning from public yards, sales, and neighboring farms.
Wallow holes and cesspoles should be drained, filled in, or fenced
off.
Runs underneath buildings should be cleaned and disinfected and
then boarded up. Straw stacks that have been frequented by sick
hogs should be burned or removed to the field and plowed under. In
fact, it is a dangerous practice to leave remnants of stacks from year
to year, and new tenants should beware of this source of danger.
Hogs that do not recover fully from cholera should be destroyed,
as they remain constantly dangerous.
1 Compound cresol solution (U. 8. P.), or a suitable substitute therefor, may be a very
satisfactory disinfectant for use against hog cholera. The substitute for compound solu-
tion of cresol (see B. A. I. Order 245, p. 5) is called ‘‘ saponified cresol solution.” Both
products contain 50 per cent of cresol. They are used in 3 per cent solution. This solu-
tion is made by adding 4 fluid ounces of the concentrated disinfectant to 1 gallon of soft
water,
16 FARMERS’ BULLETIN 834,
All animals that die on the farm, as well as the entrails removed
from animals at butchering time, should be properly disposed of by
burning to ashes, or by burying with quicklime away from streams
and low places. Unless disposed of in this way they will serve to
attract buzzards, crows, and dogs that may bring or carry away the
germs of hog cholera.
Newly purchased stock, stock borrowed or loaned for breeding pur-
poses, and stock exhibited at public fairs should be placed in isolated
pens and kept there for at least 15 days before being turned in with
the herd. During this quarantine care should be used to prevent
carrying infection from these to other pens by those who feed or
care for stock.
Hogs should not be allowed to follow newly purchased stock unless
such stock has been dipped or driven through a suitable disinfectant.
If hog cholera appears on the farm a notice should be posted at
the entrance to the premises reading “ HOG CHOLERA—KEEP
OUT,” and all neighbors should be warned so that they may protect
their herds. The infected herd should be confined to limited quar-
ters that can be cleaned daily during the presence of the disease and
sprayed occasionally with a disinfectant consisting of 1 part of
compound cresol solution to 30 parts of water, or with a recognized
substitute therefor.
PREVENTION BY INOCULATION.
Up to the present time no drug or combination of drugs is known
which can be regarded as a preventive or cure for hog cholera in a
true sense of the word. It is true that a number of preparations on
the market composed of drugs and chemicals are advertised to pro-
tect hogs against cholera or to cure hogs affected with cholera.
Many of these so-called cures have been tested by Federal or State
institutions, and one and all have been found to be worthless.
Farmers therefore are warned against investing their money and
placing their faith in hog-cholera medicines. Only one agent known
can be regarded as a reliable preventive. That agent is “ anti-hog-
cholera serum,” prepared according to the methods originally worked
out by the Bureau of Animal Industry. This serum is prepared as
follows:
Hogs that are immune against cholera, either naturally, as a result
of exposure to disease, or as a result of inoculation, are injected with
large quantities of blood from hogs sick of cholera. The blood, which
contains the virus from the sick hogs, even in minute quanti-
ties, would kill susceptible pigs but does not injure immunes; on the
contrary, it causes immunes to become more highly immune. After
the immunes are injected with virus as stated, they are called “ hyper-
immunes.” About 10 days or 2 weeks after an immune has been
HOG CHOLERA: PREVENTION AND TREATMENT: 17
hyperimmunized its blood contains a large amount of protective sub-
stances or antibodies,:and it is from such blood that anti-hog-cholera
serum is prepared.
The fact that a serum made in this way will protect hogs from
contracting cholera was first brought to the attention of the authori-
ties in the various States by the Bureau of Animal Industry in
1908-9. Following this several State institutions began the prep-
aration and distribution of the serum, and subsequently its manufac-
ture was taken up by private concerns all over the United States.
The efficacy of the serum is now recognized generally both in the
United States and in foreign countries.
While the serum is regarded as most eflicacious when administered
as a preventive, it undoubtedly has considerable curative value pro-
vided it is administered when hogs are in the very early stages of
the disease.
Beginning in 1918, the Bureau of Animal Industry conducted ex-
periments in 17 counties in 15 different States to determine the possi-
bility of reducing losses from hog cholera by a systematic campaign
embracing limited quarantine and sanitary measures and the use of
the preventive-serum treatment. In the course of these experiments
234,136 hogs were treated in infected herds, with a loss of 13.1 per
cent, notwithstanding the fact that 85,547, or 36.5 per cent, of the
number were sick, showing high temperatures or other evidences of
disease at the time of treatinent.
During the same period 19,208 hogs were treated in uninfected
herds for protection, with a total loss of only 49 hogs, or one-fifth of 1
per cent. The few deaths recorded probably were due to causes other
than cholera, and the losses from that source may be regarded as nil.
The results of these experiments are shown in the following tables:
TaBLEe 2.—Results of serwm treatment in infected herds, 1913, 1914, and 1915.
!
eye : Hogs ye
Condition of hogs and method of treatment. eecntea, Hogs died.
Hogs sick when treated: Number. | Number. | Per cent.
Ninn tame Quah ae aaeise eee cee iets seers. 25 2, 448 713 29.1
Serumyal ones seer seer cesses 1-5 eee ie! o3, 099 23, 990 28.8
85, 547 24, 703 28. 8
Hogs apparently well when treated:
Simul tam eoushseiey: see sees fe seaate* oR < 81, 289 3, 070 aH
Sober MOTD Sass os Sek BO ae. cemeine 67, 300 3, 063 4.5
148, 589 | 6, 133 4.1
Ciel eee ae SA to 234,136 | 30, 836 13,1
1The two systems of inoculation used in protecting hogs from cholera are explained
under later headings.
18 FARMERS’ BULLETIN 834.
TaBLE 3.—Resulls of serum treatment in exposed herds (apparently well when treated),
1913, 1914, and 1915.
Hogs
Mode of treatment. treated.
Hogs died.
Number. | Number. | Per cent.
Serum alone: 2.52 sei talaaaeses sa eee: ae See eee 10, 679 34 0.3
Simul taneous'.4$~. sc oe) a eee ee. eee 8, 529 15 OA
Total b. 555255552) eee eee 19, 208 49 0.2
METHOD OF ADMINISTERING SERUM.
Two systems are used in protecting hogs from cholera by inocula-
tion—the “serum-alone inoculation” and the “ simultaneous inocula-
tion.” These two systems will be discussed later. At this point it is
proposed merely to describe the mode of handling the herd and the
manner of making the injection.
Before beginning the treatment of an infected herd, the sick and
the apparently well hogs should be separated and each lot confined
in a pen or inclosure that may be cleaned and disinfected. limit
quarters that should be cleaned and sprayed occasionally wi
1 part of compound cresol solution to 30 parts of water, u
the disease has abated in the herd.
To.obtain the best results the serum must be administe
soon as the disease can be detected in the herd. Be sur
the temperature of all hogs is taken. A temperature ab
104° F. in ordinary weather and when the animal is not exe
indicates the necessity for an increased dose of serum.
TO RID PREMISES OF INFECTION.
Collect all manure in piles away from hogs and allow
Burn all litter, rubbish, and old hog troughs. ‘
After the premises are thoroughly cleaned, spray walls,
and other surfaces, including remaining hog troughs, etc., >
a disinfectant (1 part compound cresol solution to 30
water). Where hog houses are small, turn them over, exp
interior to sunlight.
Cleanliness and sunlight help to destroy infection.
Wallow holes and cesspools should be filled in, ceainet
fenced off,
All runs underneath buildings should be cleaned and ais -
fected and then boarded up to keep hogs out. i
Destroy hogs that do not fully recover, as they may be car
of cholera infection.