Title: Hog cholera and diseases resembling hog cholera
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Permanent Link: http://ufdc.ufl.edu/UF90000452/00001
 Material Information
Title: Hog cholera and diseases resembling hog cholera
Physical Description: Book
Creator: Spencer, John
Publisher: Agricultural Extension Division, University of Florida
Publication Date: 1918
Copyright Date: 1918
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Bibliographic ID: UF90000452
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
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47284993 - OCLC
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November, 1918

P. H. Rolfs, Director


The earliest recognized outbreak of hog cholera occurred in
Ohio in 1833 where presumably it had been imported from
Europe. Its spread was at first slow, but later spread rapidly,
and today is known thruout the entire United States.

Fig. 1.-Proper Method Holding Small Hogs for Vaccination.
(Axillary Space) (Original)

Bulletin 13

Florida Cooperative Extension

Statistics from the Florida monthly crop report U. S. D. A.
for the year ending March 31, 1918 show cholera losses were
$545,400. This loss exceeds the value of oranges in any county
in the state with the exception of Brevard, DeSoto, Orange, Polk,
and Volusia.
The hog losses in the United States, 70% of which should
be charged to cholera, per 1000 head, were:
1914................ ....... .......... 118.8
1916................ .. ............... 66.2
1917....................... ..... ...... 48.6
1918......... ............ ........... 42.1
The hog losses in Florida during the past ten years have
been reduced from 98 per thousand in 1917 to 90 per thousand
for 1918. In the face of the increased prices, this 8% decreased
loss is significant, and means the saving of many thousands of
Hog cholera is due to one cause and one only-the bacillus
of hog cholera, and without which the true disease cannot exist.
There are, however, many contributing influences which may
favor its spread and virulence.

These are the conditions which favor the transmission of
germs from animal to animal: Allowing hogs to run at large
so that diseased and healthy mingle; freedom of animals to
wander along lines of railways on which hogs are carried;
scattering of infected litter from cars on such railways; use of
same cars, boats, etc., without thoro disinfection; the purchase
of stock from public markets; the introduction of fresh animals
into a herd without ample quarantine; the return of swine from
fairs without regard to the same precaution; allowing butchers,
dealers, dogs, cats and birds, especially buzzards, to go into the
pens and yards where the hogs are kept; feeding of uncooked
garbage from boarding houses, hotels, etc., where infected scraps
of raw bacon and such products find their way into swill barrels.
This latter means has been responsible for outbreaks in the
Dominion of Canada where they have occurred simultaneously
at widely remote points, the same brand of bacon having found
its way to such points. A few years ago the writer traced an

Bulletin 13, Hog Cholera 3

extensive outbreak in South Dakota to a source some five miles
up stream following a deluge of rain which flooded the valley.
These and very similar instances figure largely in isolated
and apparently obscure causes of serious loss from the disease.

Upon direct inoculation of diseased blood into healthy, sus-
ceptible animals, the disease usually asserts itself inside of a
week. Where infection is taken into the system in feed and
water the period is much longer in- many cases and may extend
over a period of ten days to two weeks or even longer, depending
upon (1) the susceptibility of the animal, and (2) upon the
degree of virulence of the virus; for it is known that in both a
wide variation exists.
Hog cholera is recognized in two forms-acute and chronic.
Acute. Symptoms in the acute form vary according to sus-
ceptibility and virulence. While well marked cases usually

Fig. 2.-Early Evidence of Hog Cholera. Note Position of Two Sick Pigs
in Foreground. (From Farmers' Bulletin 834, B. A. I.)

* Florida Cooperative Extension

present a rather uniform type of symptoms and course, yet we
find young pigs under six months are usually the first to exhibit
signs of sickness and likewise are first to succumb. It is there-
fore not uncommon to find one or more young pigs dead as the
first evidence of the disease in a herd. Where sickness is evi-
dent, one, two or more will be found separated from the herd
(fig. 2) and if the weather is cold these will be huddled to-
gether and are disinclined to move; if compelled to rise they
seem to be gaunt and listless. Many frequently cough. The
temperature at this stage is 'usually high-105 to 1070F. The
normal temperature is 102 F. The bowels are at first consti-
pated and feces streaked with blood. On the second, third or
fourth day constipation gives way to profuse and fetid diarrhea
which lasts thruout the duration of the disease which is from
two to eight days, the fetid odor being highly characteristic.
Where death is delayed, a percentage of cases show marked dis-
coloration of the skin on under surface of body, thighs, inside
of fore legs, ears and snout. During the course of cholera hogs
usually reject feed, but will frequently drink cold water freely.
A few hours preceding death the internal temperature usually
falls to normal or even lower. Older hogs withstand the acute
attack somewhat longer than shoats. Eyes are usually gummed
up with gluey discharge and breathing increased.
Chronic. Chronic cholera usually succeeds the acute type
and shows itself in a modified continuance of the attack and may
run a course lasting over weeks or even months, in which pigs
do not regain their normal health and vigor but remain ema-
ciated. The hair usually peels off and in some cases the skin dies
in patches and sloughs, leaving open, raw sores. There is fre-
quently a harsh cough, with increased breathing.

The recognition of hog cholera with any degree of accuracy
is frequently dependent upon post mortem evidences, and those
are frequently similar to post mortem changes found in other
diseases in a general way. In conducting post mortem exami-
nations it is better to adopt a regular uniform system and ex-
amine each part in its natural position as nearly as possible,
and immediately after death. The surface of the body should
be carefully inspected for evidence of discoloration. These dis-
colorations consist of highly colored markings on the under side
of the belly, inside of thighs and fore legs, ears and snout, and

Bulletin 13, Hog Cholera

when present are very characteristic of cholera. They must
not, however, be confused with reddening on the under side of
the body from dead carcasses remaining on the ground several
hours after death. The discolorations are those of reddening on
the outer edges of discolored areas, becoming deeper in color
toward the center and assuming a deep birth-mark color. The
absence of these discolorations must not be regarded as proof
that cholera does not exist; in fact noticeable symptoms are
rather rare in cases which are so acute as to succumb the second
to fourth day.
Upon opening the body, note the color of the lymphatic
glands in the region of the throat. In cholera these are a deep
red color. This condition of lymphatic gland congestion will be
found thruout the body wherever encountered, especially the
lymphatic glands attached to bowels.
Lungs.-If involved, the lungs usually present highly char-
acteristic changes. These inflamed areas terminate very
abruptly, the line of demarcation being sharply drawn. Several
such inflamed areas may be present on one lobe of the lung.
Again, the surface of the lungs is usually dotted with bright
red spots varying in size from a pinhead to that of a small bean.
The covering and the upper valves of the heart may also be
similarly marked.
Stomach.-The lining of the stomach and the intestines is
usually dotted with inflamed areas, and these are generally
present thruout the lining of the intestines. The termination of
the small bowel where it enters the large bowel presents typical
button-shaped ulcers, especially in cases where death has been
delayed a few days. These ulcers are highly evident of cholera,
and are extremely rare in any other condition. Bowel lymphatic
glands are of deep red color.
Liver.-There is little or no diseased alteration of the liver.
Spleen.-Upon the surface of the spleen bright red specks
are frequently present. It is usually enlarged, softer in texture,
contains an abnormal amount of blood, and is darkened in color.
The normal spleen in the hog is about six inches long, one to
two inches wide and half an inch thick in its thickest part, and
is scarlet color in health.
Kidneys.-It is in the kidneys that we find perhaps the most
typical evidence of hog cholera and the one above all others, in
the writer's opinion, upon which positive conclusions are to be
based. The kidneys should be carefully removed from the

Florida Cooperative Extension

body. With a sharp knife split the
delicate capsule in which they are con-
tained and peel it off; then carefully
inspect the exposed outer surface of the
gland for small bright red spots not
larger than a pin point. The presence
of even one, two or half a dozen such
specks on a kidney affords the best evi-
dence of cholera. In many cases where
death has been delayed from six to ten
days from the first noticeable symptom
it is not unusual to find the kidney all
spotted up (fig. 3), but the absence of
such extensive markings must not be
regarded as no evidence of cholera.
While engaged in serum production the
writer has rarely seen a typical cholera
post mortem without kidney spots, and
has found only one other condition (An-
thrax) in which these are present.

Fig. 3.-K i d n e y Spots
Showing Evidence of
Cholera. (From Farm-
ers' Bulletin 834, B. A.

Immediately upon the outbreak of hog cholera in a herd,
healthy animals should be vaccinated and removed to non-in-
fected quarters and proper quarantine established. They should
be well supplied with good drinking water. The feed should be
light in character and of exceptionally good quality, such as
grain, milk, clean swill, and green fodder. All unnecessary ex-
citement should be avoided. All dead animals should be burned
and the premises which they have occupied thoroly cleansed and

While it is desirable to treat healthy herds as a safeguard,
the same general principles must be observed, viz., avoid excite-
ment or overheating, and insist upon careful handling, and above
all be liberal in the use of serum and virus. Better err on the
side of safety by the extravagant use of serum than on the side
of economy, which is usually expensive in failures from under-

Bulletin 13, Hog Cholera


Two methods of vaccination have been adopted-the single
or serum alone treatment, and the serum simultaneous method.
The former consists of injecting a dose of serum only, which
affords only temporary protection extending over a period of a
few weeks at most, while the latter consists of a dose of serum
and also of virus at the same time but in different parts of the
body. The simultaneous treatment properly handled affords
permanent immunity and to animals so treated permanent pro-
tection against cholera.
Much judgment must be exercised in the selection of suit-
able sick animals for vaccination to avoid disappointing results.
The writer concluded from personal observations that animals
showing evidence of cholera rarely yield to serum treatment,
but that a satisfactory saving could be made by the injection of
large doses of potent serum even when the temperature was
high, with no other evidence of cholera existing. We recall one
special herd so treated, consisting of about 100 animals, in
which several had died of cholera. Those animals which were
visibly sick and had high temperatures all died; 60 percent of
those showing high temperatures only were saved, and 100 per-
cent of those showing no evidence of sickness with no rise of
temperature lived, as did also two healthy, unexposed shoats
which were vaccinated and turned in with the sick hogs.


Certain precautions must be observed in order to insure
satisfactory results. Hogs to be vaccinated should be handled
gently and above all avoid excitement or overheating, for ex-
perience has shown that recently treated hogs when immediately
driven and become heated lose the desired immunity very quickly,
and in fact a few die from the actual results of serum injection.
Pregnant sows require careful handling, on general principles.
Where large numbers of hogs are to be vaccinated the same day,
it is best to separate in smaller lots of about 25 each, thereby
lessening the period of close confinement and a corresponding
lessening of excitement.
Site of injection should be thoroly cleansed with soap and
water and bathed with tincture of iodine. Hands of operators

Florida Cooperative Extension


Fig. 4.-Proper Method Holding Small Hog for Flank
Injection. (Original)

should also
be thoroly
scrubbed; in-
struments ster-
ilized and not
again allowed
to come in con-
tact with con-
or needles
should not be
immersed in
antiseptic solu-
tions between
injections of
either serum
or virus, but
preferably re-
turned to a
normal salt so-
lution between
each operation.
Such a solution
is easily made
b y dissolving
one ounce of
coarse salt to a
gallon of boil-
ing water, and
used cold.

The locations most commonly selected for vaccinating are
the loose tissue about the flanks (fig. 4), under the fore legs
(fig. 1), and behind the ears. Heavy stock, especially pregnant
sows in which it is undesirable to cast, may be snubbed up by a
snubbing rope and injected in the loose tissue on sides of neck
and behind the ears (fig. 5.). It is unwise to inject very large
doses all at one spot or yet to inject cold serum. This may result
in failure to absorb readily and cause an abscess or slough.

Bulletin 13, Hog Cholera

Fig. 5.-Proper Method of Snubbing Heavy Hogs for Vaccination.
Virus also must never be injected in the same place as serum;
the former would be neutralized and permanent immunity lost.

From time to time reports become circulated of the evil or
unfruitful results of vaccination, and these can easily be traced
to the proper error. Where vaccinated pigs are subjected to
excitement and overheating prior to and subsequent to treat-
ment, desired results are not obtained. We have previously
referred to the varying degrees of susceptibility existing in dif-
ferent animals both in the individuals and strains of virus. This
can be accounted for largely by the past history. Undoubtedly
a degree of immunity against disease is inherited. The progeny
of immune sows certainly resist highly potent virus while they
are sucking, and gradually lose that protection in later life,
while those removed from infection for several generations are
highly susceptible. Again, while serum is carefully standard-
ized, the serum test pigs upon which the serum is tested against
virus may be and usually are from sections where cholera has


Florida Cooperative Extension

existed for a long period and recurs annually, or are the progeny
of immune sows. Consequently they are not so highly sus-
ceptible. Most of the serum-producing plants in this country
are operating in strictly hog raising sections where cholera is
most prevalent, and where wholly susceptible stock is practically
Again, virus varies greatly in its degree of virulence. We
have personally handled strains of virus which would develop
cholera with the greatest regularity on the third and fourth day.
while others would fail to produce the same results in three times
that period. Therefore, we recognize three conditions which
cannot be foreseen in hog vaccination:
(1) Extreme susceptibility of pigs; (2) impotent serum or
one not fully up to standard; (3) unduly virulent virus.
Any one of these conditions alone against an ordinary
standard dose of serum would be hazardous. Any two of the
above named conditions would induce a percentage of cases of
cholera; while all three would certainly bring about the develop-
ment of cholera in a previously healthy herd.
Having discovered these conditions in actual practice, we
have heretofore advocated giving a dose of serum alone first,
followed in ten days by full serum simultaneous treatment. We
now believe this method can be greatly improved upon by largely
increasing the dose of serum and at the same time give a liberal
dose of virus instead of making two operations. We believe it is
a mistake in field practice to curtail the dose of virulent blood
with a view of lessening the risk of bad results, for by this
practice we are liable to fall short of permanent immunity.
With regard to permanent immunity induced in very young
pigs, we are in grave doubt, but have no data at hand to sub-
stantiate that belief. We do know, however, from actual test
that young sucking pigs, the progeny of recently immuned sows,
will withstand the injection of highly virulent blood alone, but
question permanency of immunity conferred by that method. It
is safe, however, to believe that serum simultaneously treated
pigs of 80 to 100 pounds will resist infection thruout their life-

The Bureau of Animal Industry has published carefully com-
piled statistics, and state that out of 3235 sows treated with
serum alone in infected herds, 8 percent aborted, and that of

Bulletin 13, Hog Cholera

1357 given simultaneous injection 7.2 percent lost pigs, and of
126 serum alone treated sows in exposed herds 1.5 percent
aborted and none of the 38 simultaneously injected animals lost
their pigs. With regard to the effect produced on fertility, it
has been found to have approximately no effect, as 95 percent of
2362 sows were successful producers after serum and virus
treatment, while 94 percent of 1840 untreated sows also bred
successfully. Immune sows produce immune pigs, and these
retain their immunity until weaned.

The writer has just received the latest published informa-
tion on investigations by the Bureau of Animal Industry con-
cerning sources and channels of infection in hog cholera, and we
take the liberty of reprinting verbatim the summary and con-
clusions of these findings.
"Altho the data obtained from these experiments is not
sufficient to warrant sweeping conclusions, the results are never-
theless quite suggestive, and they serve to bring out some inter-
esting points which may be summarized as follows:
"(1) The eye and nose secretions, the blood, the urine, and
the feces of cholera-infected pigs were tested on the first, second,
third, fifth, seventh, and ninth days after infection. When
injected, the eye and nose secretions and fecal suspensions
were found to be infectious on the third day; the urine
was quite regularly infectious by the fourth or fifth day and the
blood was infectious as early as the first day. When fed and
when scattered in pens, the freshly collected secretions and
excreta were noninfectious as a rule. Secretions and excreta
which are held at room temperature (600 to 850F.) for 24 hours
remained infectious when injected. When the secretions and
excreta were held at the same temperature for 48 hours the
urine and feces remained infectious, but the eye and nose secre-
tions were no longer so. It might appear, therefore, that outside
the animal body the virus in the eye and nose secretions suc-
cumbs more quickly than the virus in the urine and feces, but
such a conclusion is not justified by these experiments, as the
virus from the eye and nose was allowed to dry on swabs. This
point requires further study with the virus from the different
sources held under identical conditions. Finally, it should be
noted that the eye and nose secretions may be infectious before
there is any visible discharge from the eyes or nose.

Florida Cooperative Extension

"(2) Susceptible pigs were exposed by association with
cholera-infected pigs for 48-hour periods on the first, third, fifth,
seventh, ninth, and eleventh days after infection. With the ex-
ception of those exposed on the first and second days-that is,
during the first 48-hour interval-all of the exposed pigs con-
tracted hog cholera. Other pigs which were exposed to cholera-
infected pigs at 17 and 21 days contracted hog cholera. Cholera-
infected pigs therefore may transmit the disease by contact at
practically all stages of the disease, even in the period of incu-
bation, before the appearance of visible symptoms and before the
animal can be recognized as sick.
"(3) Susceptible pigs were exposed by being placed in
pens with pigs which had suffered from typical attacks of hog
cholera but had recovered. Other susceptible pigs were inocu-
lated with blood drawn from the recovered pigs. Four re-
covered pigs were tested in this way to determine whether they
harbored the virus of cholera within their bodies and might
act as carriers of the disease. None of the pigs exposed to the
recovered pigs, either by association or by blood injection, de-
veloped hog cholera. The exposed pigs were later proved to be
susceptible by virus injection.
"(4) Susceptible pigs were exposed for long periods of
time to pigeons, which passed daily from a heavily infected pen
only 10 feet away and which contained sick and dying pigs, to a
pen containing susceptible pigs. The exposure in these experi-
ments was severe, as the pigeons were afforded every opportunity
to carry the infection over a very short distance. Notwithstand-
ing this, none of the exposed pigs developed cholera. All of the
exposed pigs were later proved to be susceptible either by virus
injection, by association directly with sick pigs, or by exposure
in an infected pen. These experiments extended thru the fall
and well into the winter. While the assumption would hardly
be warranted that pigeons never convey hog cholera, it does
not seem likely that they are often concerned in the spread of
this disease.
"(5) Rats were fed on the meat of cholera hogs for periods
of 5 to 21 days. The rats were then killed, their entire bodies
chopped up, mixed with bran mash, and the mixture was fed to
susceptible pigs. None of the pigs thus fed contracted cholera.
The pigs were proved to be susceptible by subsequent virus

Bulletin 13, Hog Cholera


There are a number of diseases that affect the hog in very
much the same way as does hog cholera. However, such troubles,
which are non-infectious, do not extend beyond the herd or herds
first attacked, or animals fed under same or similar conditions.
As the loss from these causes is frequently large, any one of
the following might easily be mistaken for hog cholera.


This rather common and largely overlooked infectious dis-
ease of pigs assumes various forms according to just what part
of the body is attacked. The form most prevalent among the
hogs in Florida is confined to the intestinal tract and known as
necrotic enteritis, and is often mistaken for cholera. This con-
dition is observed only in pigs from about six weeks to seven
months of age. The organism Bacillus necrophorus, which pro-
duces this condition, inhabits the intestinal canal, and being
expelled in the fecal discharge, develops and flourishes in damp
unsanitary places. When introduced into a wound either on the
body or in the digestive tract, it produces its characteristic
necrotic (dead) lesions.
Symptoms.-To the casual observer the disease resembles
cholera, but a close study and an accurate diagnosis, together
with post mortem evidence, will distinguish the difference. The
animals are depressed, appetite is in abeyance or wholly want-
ing, the pigs become unthrifty, emaciated and weak. Diarrhea
may be present early in this form, but lacks the characteristic
odor peculiar to that of cholera. The temperature is generally
normal or subnormal, mortality exceedingly high. Post mortem
evidences are chiefly confined to the lining of the bowels, which
show characteristic grey raised patches which can be readily
scraped off, exposing a collection of cheesy substance. When
these areas are extensive, absorption of the food for the sus-
tenance of the body is interfered with and the animal dies from
lack of nutrition.
Differential Diagnosis.-Absence of uniformly high tem-
peratures, skin discoloration, button-shaped ulcers confined to
the ileocecal region and characteristic kidney specks serve to
distinguish the disease from cholera.

Florida Cooperative Extension

Prevention.-Prevention consists of better sanitation and
the destruction or removal of infected surroundings. Nearby
mud puddles should be filled, old wooden floors and troughs re-
moved, or preferably new quarters provided. There should be
a rigid separation of the healthy .from the diseased animals, and
reliable disinfectants used freely. Lime freely applied to pens,
lots, etc., will be found effective.


A condition that is by no means uncommon among swine
which are fed town-collected garbage is caustic poisoning. This
poisoning comes from the too free use of caustic soaps in dish-
washing, where it finds its way into the garbage cans.
Symptoms.-The symptoms produced by caustic poisoning
are very similar to those of hog cholera. Animals, regardless of
age, are taken suddenly ill, refuse feed, have unquenchable
thirst and exhibit high fever. Early in the attack diarrhea
asserts itself, and it is frequently blood-stained. Mucous mem-
branes of mouth and anus are frequently highly inflamed; vomit-
ing frequently present; death taking place on second, third or
fourth day, depending upon the amount of poison taken in and
its concentration. When confronted with this condition in a
herd of swine, the source of feed should be carefully considered
and examined.
The writer has witnessed rather widespread loss from this
cause where hogs have been held in quarantine as cholera sus-
pects, and where an examination of their feed has revealed por-
tions of cans of undissolved caustic in the swill.
Post Mortem.-Examination after death due to caustic poi-
soning is usually confined to those portions of the mucous mem-
branes of the mouth, throat, oesophagus, stomach and bowels
which have been inflamed by the caustic action of the poison.
There is an intense inflammation extending from mouth to anus.
Treatment.-First remove the cause. As the offending
caustics are highly concentrated alkaline substances, dilute acids
should be administered in a drench to animals so affected. Vine-
gar is good for this purpose and should be given in half ounce
doses highly diluted. This should be followed by a dose of castor
oil, and for a 100 pound hog, 1 to 3 ounces is a dose, after which
give 20-grain doses subnitrate of bismuth with five to ten grains

Bulletin 13, Hog Cholera

powdered opium every eight hours until relief is secured. Abun-
dance of cool drinking water will also materially assist. The
feed should be-of a light, easily digested nature. Milk, oat-
meal and green material are good feeds for animals so affected.


This condition in hogs is usually associated with faulty
feeding and can be traced to errors in diet, such as allowing
musty grain, rotten fruits and vegetables, or over-stimulating
concentrated feeds to be devoured in large quantities.
Symptoms.-Vomiting is far from uncommon; bowels are
irregular in their action-at times constipated and again loose;
condition falls off rapidly.
Treatment.-In the management of this form of indigestion
strict attention must be given to the character of the feed. It
should be given at regular intervals and in moderate quantities,
which, together with sanitary surroundings, is usually all that
is called for.
Twenty-drop doses dilute hydrochloric acid (not concen-
trated) to each 100 pound hog assists digestion in such cases.
Constipation is assisted by injection of warm water and proper
diet rather than by purgatives. Buttermilk is good for hogs
bothered with indigestion.


This is a very acute and fatal malady affecting hogs, es-
pecially under southern conditions, and is due to constant feeding
on over-rich and concentrated feeds. This is especially true
when such feeds have been grown under conditions favoring
vegetable bacterial development which possess poisonous sub-
stances either in toxines or alkaloids. The functions of the liver
are important and well understood, and among these none are
more important than its ability to attract and arrest poisons,
which when in excessive quantities, overcome its function.
Causes.-Highly concentrated and fungus contaminated
feeds given for long periods, and stagnant drinking water con-
taining animal and vegetable decomposition, are the usual causes
of this disease.

Florida Cooperative Extension

Symptoms.-In the lower animals the accurate diagnosis of
liver diseases is difficult and poorly understood, consequently
frequently overlooked sufficiently early to be of use. The earliest
indications of liver congestion leading to atrophy is a general
dullness with loss of appetite. In hogs the ears are drooping and
the head depressed, the eyes are dull and sunken, with frequent
collection of mucus. The visible mucous membranes are yel-
lowish (jaundiced), the bowels are constipated and the urine
highly colored (brown or yellow). As the stomach and upper
intestinal tract is irritated, there is a tendency to swallow such
foreign substances as earth and sand in large quantities, which
leads to vomiting and diarrhea. The latter usually hastens
death. Death usually takes place in from three to ten days from
first noticeable symptoms. The mortality is very high.
Post mortem evidence of atrophy of the liver is usually con-
fined to the liver and its surrounding. The gland is shrunken
in size, solid to the feel, and is heavy in weight, and of a deep
yellow color. There is frequently patches of congestion of the
bowels. The spleen is frequently three or four times larger than
normal, and in cases we have personally opened, the stomach
contained large quantities of sand. Its mucous coat is pale in
color; peritoneal fluid is over abundant, and of a yellowish
bloody color.
Treatment is limited to preventive measures. When such
conditions are revealed by clinical evidence or post mortem
findings, no time should be lost in examining the character of
the feed and water. A mixed diet rather than one highly con-
centrated must be substituted. Green feed, velvet beans, pota-
toes, etc., should be selected. Drinking water should be pro-
vided from unquestionable sources, preferably from deep wells
or running streams.
Differential Diagnosis.-Atrophy of the liver may be dis-
tinguished from hog cholera by the absence of uniformly high
temperature at the offset of the former, by the uniform persist-
ent diarrhea of the latter, together with its characteristic odor;
by the jaundiced colored mucous membranes of liver atrophy,
and general post mortem findings, which are chiefly confined
to the liver in atrophy; and absence of kidney spots and bowel
ulcers, which always go with cholera.

Bulletin 13, Hog Cholera

Of all domestic animals, the hog suffers most from ravages
of worms, which in a southern climate is a severe handicap in
successful hog raising.

(Ascaris suilla)
This round worm which in-
habits the intestinal canal is prob-
ably the most common found in the
hog, and except they are present
in large numbers, rarely give rise
to symptoms which would lead to
a suspicion of their existence. The
adult worm is round, about six to
ten inches in length, is a pinkish or
yellowish white, and tapers at both
ends. (Fig. 6.) They are not
blood suckers but feed upon the
intestinal contents.
Symptoms. -When in large
numbers this parasite gives rise to F. -Rnd Wr
Fig. 6.-Round Worms (Asca-
a chain of symptoms suggestive ris suilla) (From Lynch's Dis-
of its presence, such as unthrifti- eases of Swine.)
ness, loss of appetite, diarrhea, and the passage of worms in the
feces. Colicky pains with occasional nervous disturbances may in
extreme cases be exhibited.
Treatment.-In order to successfully combat the ravages.of
worms, as with all parasites, it is necessary to cut off the source
of supply. See that no stagnant water is used for drinking
purposes. Fresh water should be available, with clean quarters.
Several remedies can be used, but the writer has found excellent
results from the use of the following mixture:
Fresh powdered areca nut ..................... 2 parts
Fresh powdered worm seed..........................2 parts
Fresh powdered kamala................ .......... .1 part
Dose for a 100 pound hog is a heaping teaspoonful once
daily in sloppy feed until four to six doses have been given. All
fecal matter should be collected and burned during and imme-
diately following treatment. Good results can also be obtained
from 5 grain doses each of calomel and santonine per 100 pound
weight daily or every second day for three or four doses. This

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should be mixed in meal and each animal dosed separately.
Spirits of turpentine is also an active destroyer of worms and
should be given in half ounce doses for hogs of 100 pound weight.
Its use must not be long continued on account of its toxic effect
upon the kidneys. Whatever treatment is pursued, success will
only follow in protecting hogs against renewed infection by
placing them in non-infected quarters and
supplying good sound feed and clear uncon-
taminated drinking water.
(Echinorhynchus Gigas)
Another important intestinal worm
found in southern hogs is the thornhead
worm, which is a parasite of hogs only. This
is a large, round worm, .the female measur-
ing from 8 to 12 inches; males 3 to 4 inches.
(Fig. 7.) This round worm differs from
others in that it fastens itself securely into
the lining of the bowel.
Fi. 7. i Life History.-Adult female lays its
Fig. 7. Thornhead
Worm (Echinor- eggs in the bowels of the hog, and from here
hynchus gigas). passes out to the ground. These eggs are
(From Newman's
Animal Para- eaten by the white grub worm, and here the
sites) eggs hatch and pass thru their larva and
pupation stage. The grub worm is eaten by the hog, liberating
the young worm which again becomes the adult parasite.
Symptoms.-As with the round worms, the presence of con-
siderable numbers of thornhead worms are necessary to produce
symptoms of digestive disturbances. The pig loses flesh; is
usually nervous; has variable appetite; constipation is alternated
with diarrhea. Nervous symptoms may be marked by extreme
irritability, twitching of the muscles of the neck, convulsions
resembling epilepsy, which if severe may result in death.
Post Mortem.-Post mortem reveals numerous ulcers of the
bowels, which should not be confused with those of the ulcers of
hog cholera. Those of the thornhead worm are found along the
course of the small intestines, while those of cholera are most
severe at or near the ileocecal valve.
Treatment.-Prevention here plays an important part. Keep
the animals away from old lots and manure piles where the grub
worm is common; rather feed hogs on plank floors or new pas-

Bulletin 13, Hog Cholera

Turpentine has been found to be very destructive to this
parasite, but is open to the objection of irritating the kidneys
if used too long. A good practice is to give from a teaspoonful
to a tablespoonful spirits of turpentine once daily for three
doses and follow with a brisk purge of castor oil. As these
agents mix readily with milk their administration should not be
difficult to hungry hogs.
When it is desired or necessary to drench hogs, great care
must be exercised to avoid choking. The writer has found that
by snubbing hogs up by a rope attached to the upper jaw, hold-
ing the head moderately low, and passing the fluids gently back
on the tongue from a small metal dose syringe equipped with a
five inch pipe, the operation can usually be performed with a
fair degree of safety.


Hog cholera is a highly communicable disease of swine and
is due to one cause only, the introduction of an unknown filter-
able virus into susceptible subjects. This is materially aided by
such influences as lack of good sanitation, overcrowding, undue
exposure to sick and other immediate surroundings. The disease
runs a definite and usually fatal course. Immunity to the disease
by either natural or artificial influences is permanent in all but
the very young. The success with which it is handled depends
wholly upon an early and accurate diagnosis which must be based
largely upon the history of the invasion, coupled with a chain
of specific symptoms and post mortems heretofore outlined.
These briefly summed up are high temperatures, constipation,
subsequented by persistent fetid diarrhea, discharge from eyes,
cough, etc., with uniform congestion of the lymph glands of the
body, characteristic button-shaped bowel ulcers in the ileocecal
region, and kidney specks.
Hog cholera is to be distinguished from a variety of dietic
disorders and poisoning from alkalies and possibly other chemi-
cals which may find access to the feed. Powdered soap has been
found to produce a series of symptoms closely resembling those
of hog cholera.
As between chronic cholera and a severe infestation of in-
testinal worms, one must be guarded in a too positive diagnosis.
The general outlook is closely associated as regards symptoms.
The presence of large numbers of worms in the bowels justifies
active measures against those in any case. The past history of

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the herd will assist in a diagnosis, for all cholera outbreaks are
marked by considerable loss, especially at the offset, with many
or all the post mortem evidences, especially ileocecal ulcers and
kidney spots.

Locating the hog lots and pens away from public highways
and running streams.
Avoid visiting farms where sick hogs exist, and restrict
traffic as much as possible to your own pens and yards.
Do not expose healthy herds to freshly purchased stock until
a long period of quarantine has been made, say thirty days.
In case of an outbreak in your herd, vaccinate promptly, and
under best possible conditions.
Be liberal with the dose of serum.
Burn dead animals and make free use of disinfectants, 2%
to 3% cresol.
One of three things is accomplished by vaccination-noth-
ing, immunity, or hog cholera.

Hog raisers are earnestly cautioned against the adoption of
much advertised so-called guaranteed cures and preventive
measures against cholera other than officially tested hog cholera
serum. These remedies have been fully tested as they have ap-
peared on the American market, none of which have proven the
claims made for them by their makers. There is no known
remedy which will protect or immunize hogs against cholera
except the anti-hog cholera serum.

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