Mucosæ not necessarily Mucosæ congested Mucosæ deeply
congested congested, dark red,
violet
Petechiæ on snout, Petechiæ on snout, Petechiæ extensive
eyes, mouth, etc. eyes, mouth, etc.
Necrotic ulcers on Necrotic ulcers rare Necrotic ulcers less
snout, mouth, skin, frequent
etc.
Furred tongue, vomiting Vomiting less likely Vomiting not uncommon
common
Temperature high in Temperature high in Temperature very high,
acute cases (104° to acute cases 107° to 109°
108°)
Lies on belly mostly, May lie on side May lie on side
abdomen hot, tender
Moves stiffly, feebly, Stiff but less so, Stiff, weak, paraplegic
unsteadily with Paretic.
grunting, may be
paraplegic
Bowels 1st costive, Diarrhœa less marked, Diarrhœa usually sets
fæces molded, glazed; may be entirely in
2d or 3d day, or absent
before death,
diarrhœa, profuse,
watery, fœtid,
bloody, black on
slops,—yellow on corn
(maize)
Everted anus dark red Anus may not be deep Anus may be less red,
red, less everted less everted
Cough often present, Cough, hard, frequent; Cough absent, save in
hurried breathing wheezing breathing. latter stages with
Auscultation and pulmonary
percussion may show consolidation
lung consolidation
toward lower border.
May bleed from nose
Spleen slightly Spleen usually little Spleen enlarged, soft,
enlarged altered grumous
When death is deferred Necrotic, button-like Necrotic ulcers on
1 to 2 weeks, ulcers on cæcum bowels rare
necrotic button-like rarely marked
ulcers on ilio-cæcal
valve, cæcum, colon,
or ileum
Lobar pneumonia Lobar or lobular Pulmonary and enteric
uncommon pneumonia a marked inflammation rare
lesion
Kills rabbits (5 to 7 Kills rabbits (1 to 12 Kills pigeon (3 to 8
days) and Guinea pigs days), Guinea pigs (1 days), rabbit (4 to 8
(7 to 12 days). to 4 days), pigeon days), Guinea pig
Pigeons sicken but (48 hours) resists
survive
Blood serum of hog
cholera patient
causes agglutination
of bacilli in
cultures; (not
constant, occurs with
other bacilli)
_Dry, warm beds_ with plenty of _air_ and _light_ are essential to
vigorous health and the usual damp, filthy, dark pens are depressors of
the vital forces and virtually invitations to hog cholera as to other
diseases. The close packing of swine under manure or under rotten piles
of straw where they often suffocate each other is to be carefully
guarded against. It is a sufficient commentary on this to say that for
every kilogramme of its body weight, the horse consumes daily 13,272
grammes oxygen, the cow, 11,040 grammes, and the pig, 29,698 grammes.
This is in perfect keeping with the high normal temperature maintained
by the latter animal. In the interest of health the pig requires twice
the breathing space for every 100 lbs. of his weight that is demanded by
either ox or horse. What violence is done to this demand of nature in
the daily treatment of the hog!
_Fresh, sound, wholesome food_ is no less a _desideratum_. Yet the
omnivorous pig is condemned to become the scavenger for the kitchen, the
stable, the feeding pen, the slaughter house, the creamery, the sugar
works, the brewery and even the rendering works. Whatever is considered
unfit for human use is thrown into a swill barrel, and as this is never
emptied it becomes the field of endless decompositions with the
production of the most varied toxins, ptomaines and enzymes. Many of
these chemical toxic products cause gastro-intestinal inflammation with
vomiting, bloody diarrhœa and tenesmus, and derangement of the nervous
and other functions as manifested in weakness, staggering, dulness,
stupor, etc. Death may follow in a few hours and the cases are set down
as acute forms of hog cholera, rather than the simple poisoning that
they are. All the same they pave the way for the attack of hog cholera
if its germ is present even in a form of little potency. All such foods
should, on the contrary, be fed fresh and after boiling.
_Salt_ in excess, the _brine of salt meats or fish_ (containing toxins),
the _powdered soaps_ used in kitchens and added to swill, _mouldy bread,
cotton seed meal_ fed in any considerable proportion in the food, and
even an exclusive diet of _corn_ (maize), must be guarded against.
The crowding of many pigs in a small yard where they root continually
in each others’ droppings and their own, should be avoided. Individual
pens, or pens holding two or three only and kept clean are to be
preferred, and still more a wide grassy range where they may escape
from their own filth. The long feeding trough should be discarded in
favor of one into which the pig can introduce his nose only. The nose
itself will introduce filth ferments, but, where there are not
specific-plague-germs, it is the quantity that tells and the exclusion
of the foul feet is an important consideration. To these various
poisonous products of saprophytic ferments it often happens that the
older swine have by continuous exposure, acquired a comparative
immunity, while the young growing pigs perish in large numbers.
Feeding pigs in confinement, without green or animal food is very liable
to induce costiveness and indigestion which pave the way for the inroad
of the hog-cholera germ. A certain allowance of green food, slops, and,
above all, a variety of food constituting a well-balanced ration are
always desirable.
Again, the constitution of the pig is often material. On the continent
of Europe it is the high bred English pigs that suffer most, and in all
cases a lack of the rugged vigor attained through an active, open air
life lays the system more open to a violent attack. Too close breeding
must be similarly avoided, together with breeding from the immature, the
weak and the debilitated. In this connection it is important to rid the
herd of parasitisms which not only weaken the system and lessen the
power of resistance, but by the bites or the inflammation induced, open
channels for the introduction of the hog-cholera bacillus.
_Prevent the Introduction of the Bacillus._ The above precautions are
important in obviating infection and favoring a milder type of the
disease when the germ has been introduced, but they are but palliatives
at best, and will not hinder the development of a plague in the presence
of an active and potent virus. Adopted alone they are worse than useless
as a means of extinction of the germ: they tend to preserve it. The
exclusion of the hog-cholera germ is the one essential thing in
prevention and whatever comes short of this must have at best but a
partial effect.
Avoid pens, pastures or streams that drain swine enclosures higher up.
Discard all provender or litter that has come in contact with other pigs
or their products. Allow no visitors to the herd such as butchers,
dealers, drovers, that have habitually come in contact with other herds.
Exclude as far as possible domestic animals (dogs, sheep, cattle, fowls,
pigeons), and even vehicles coming from places where hogs are kept. Wild
animals such as buzzards, and other carrion feeders, must be especially
guarded against. Wild rabbits and hares (jack rabbits), skunks, wood
chucks, minks, rats and mice should be exterminated. Small birds and
flies are difficult to deal with but the latter may be destroyed by
acids, copperas, or sulphites on the manure and the former may even be
exterminated when hog-cholera exists in the vicinity.
Sows should not be sent from herd to herd for service or otherwise, and
any swine that have been hired out, or sent to an exhibition, and all
that are acquired in any manner, should, on arrival, be excluded from
the herd and held in quarantine, well apart for three or four weeks, and
finally washed with carbolic acid soap before they are admitted.
The pestilential prevalence of hog cholera and other swine plagues
to-day is largely the result of the great industrial and commercial
activity of modern times. In America the disease was comparatively
unknown until after 1830, and in Europe even later. But with the advent
of steamboat and railroad, the few pigs raised in separate pens, or
secluded localities, and killed and cured near by, gave place to the
large herds, sent when fattened to great markets where pigs were
collected from distances of many hundreds of miles, the stock animals
and the fat occupied in succession the same boats, cars and yards, and,
as a matter of course, the virulent germs were concentrated and diffused
through the infected places and things. We cannot go back to the
antiquated safer methods, but it would be possible to so regulate our
commerce, that the evil could be reduced to a minimum. Separate cars,
loading banks, chutes, alleyways, and yards can be reserved for fat
swine going to immediate slaughter and no animal having passed through
any of these should be allowed to be taken out for stock purposes,
unless it has been passed through a rigid quarantine. The places and
things used for such fat swine should be disinfected at intervals, and
the manure and offal should be disinfected, or exposed to a boiling
temperature for a sufficient length of time before removal from the
premises. Stock swine on their part should be shipped only on a
certificate of the complete immunity of the herd and locality from which
they come from swine epizoötics, and of the roads or vehicles by which
they reached the shipping point. They should be debarred from all yards,
loading banks and cars or boats used for fat hogs, and admitted only to
such as have just passed through a thorough disinfection. They should be
sent directly to their destination, or if to a market, for purposes of
sale, it should be well apart from that used for fat swine, and the
loading banks, chutes and yards should be entirely distinct and should
be thoroughly disinfected on every occasion after use. The millions now
lost yearly from swine epizoötics might well warrant the inconvenience
and expense entailed by such precautions. Heavy penalties should be
imposed on those shipping pigs from infected localities, on those making
false certificate, and on all who in any way violate the law.
Independently of State or local authorities the stock owner can do much
to protect himself. He can make a number of pens large enough to hold 2
or 3 pigs each, safely fenced off from one another and so constructed
that no drainage can take place from pen to pen. Then in winter in the
absence of flies, and with rats, mice, and birds excluded the
opportunity for the extension of infection from pen to pen can be kept
at its minimum. All pigs must be kept apart from the manure heap, and in
summer the manure must be so treated as to destroy the larvæ of flies.
All food and water that might convey infection must be guarded against.
Then if one pig is attacked it will only be necessary to destroy it and
its two fellows in the same pen, and even if those in adjacent pens are
killed or quarantined the loss will be a trifle as compared to the ruin
of the whole herd, as usually happens. Prompt disinfection of the pens
and manure is imperative, and the same would apply to the person and
clothes of the attendant, and to all stable utensils.
_Immunization_ by injection of _sterilized products_ of the bacillus,
has not proved satisfactory. In 1880 I applied this to two pigs, causing
a transient fever, after recovery from which, the subjects resisted
exposure to infected pens and pigs, and even virulent inoculations. But
they failed to thrive well. Later experiments by Drs. Salmon and
DeSchweinitz respectively, also proved unsatisfactory. The latter
separated and injected the enzymes, but lost 50 per cent of his cases,
the survivors proving immune, with the drawback of troublesome local
lesions. The enzymes obtained from cultures in milk could be used safely
on guinea pigs in the dose of 0.01 grams and in some cases even up to
0.04 securing immunity. But the great risk of an overdose, the frequent
local lesions, and the subsequent unthrift, have prevented the adoption
of the method.
_Disinfection._ The experiments of the Bureau of Animal Industry show
that, apart from freezing, _four months in the soil_, serves to render
the bacillus harmless.
From .75 to 1 per cent of quick lime added to soil in the form of lime
water, destroyed the virulence in 11 days.
Lime can be employed as a thick whitewash on pens, fences, yards, etc.,
the precaution being taken to see that it is newly burned, caustic and
applied in sufficient amount. Lime that has been kept absorbs carbon
dioxide and loses its disinfectant property. If ¼lb freshly made
chloride of lime is added to each gallon of the caustic lime white wash
the certainty of success is insured. Lime water has the advantage of
being applicable to grassy surfaces, without proving hurtful to the
vegetation. For buildings and yards it furnishes a ready means of
estimating the thoroughness of the application.
_Sulphuric acid_ (1:100 or 1¼ oz. to 1 gallon) makes a good disinfectant
for buildings and yards. Like lime this can be used freely without fear
of poisoning the animals.
_Carbolic Acid_, 5 per cent, can be used with great safety. The Bureau
of Animal Industry advises the combination of this with sulphuric acid,
which adds greatly to its solubility.
_Formalin_ may be employed, diluted one to forty of the solution (1 per
cent of the gas) in buildings and on woodwork generally. It may also be
applied in the form of gas by heating the solution in closed rooms. Like
carbolic acid it is especially applicable to cars, boats, and other
vehicles.
_Corrosive Sublimate_ (1:500) makes a convenient and cheap disinfectant,
with the drawback that it is poisonous, and destructive to metals.
_Mercuric Iodide_ though more potent is also more expensive. Blue stone
(2:100) and zinc chloride (10:100) are also effective but poisonous.
The failure to _stamp out_ hog cholera in England and America has been
largely chargeable on the appointment of laymen to do the work of the
expert, and no less so on the attempt to deal with the disease in hogs
in transit or in the market rather than in the farm where they have been
raised or kept. Let the fat and stock markets be kept rigidly apart,
together with the means of conveyance to and from these, and let no
stock swine start for a market or destination without a certificate of
the soundness of the locality from which they came, and the purity of
the means of transit, and we shall have taken a long step toward the
final extinction of the pest.
State limits and rights stand in the way of successful work, but this
can be partly met by a frontier supervision by national officials, and
should be further, by a prompt and hearty coöperation of the sanitary
officers of the two states involved. When it becomes possible to trace
infecting hogs, back to the infected place in another commonwealth, and
punish the offender who shipped them, we shall be within sight of a
satisfactory control or extinction of hog cholera.
_Extinction of Hog Cholera in Herds and Districts._ As in all deadly
plagues this should be a recognized governmental function to be carried
out at public expense. It is a question of political economy and its
neglect is subversive of prosperity not in Agriculture alone but in all
public industries whose workers must subsist on the fruits of the soil.
The $10,000,000 lost yearly by the farming community, is a dead loss,
not to agriculture alone, but to the prosperity of the nation, the
markets of which would be revived and improved by such a yearly sum
expended.
The existence of the disease at any point should be reported by the
stockowner or guardian, under penalty in case of failure. When the
nature of the outbreak has been certified by the expert, the district
should be scheduled, and the herd appraised, slaughtered and all
products disposed of in such a way as to prevent any escape of
infection. The carcasses may be burned, buried deeply, or boiled and
rendered. The buildings, yards, utensils, fences, manure, cesspools, and
infected fields should be thoroughly disinfected, or secluded from all
animals for a year. The owners of the herd should be indemnified
according to appraisment, and not to exceed ¾ths of the actual market
value, provision being made that no award shall be made if the herd
sickened within a fortnight after their arrival from another State, or
in case the owner, has concealed the existence of the illness, or has
otherwise deliberately or carelessly contributed to its spread.
Many minor rules and restrictions will be required to fit the general
measures to individual cases and local conditions, and these require the
direct supervision of an expert, and not of a mere business manager or
layman.
_Therapeutic Treatment._ With state, county or municipal measures for
the extinction of hog cholera, treatment is to be condemned, as
calculated to encrease and spread the infection. But until the states
can be educated out of the past wasteful system, into economical
measures of extinction, the swine breeders are entitled to whatever
salvage they can secure through therapeutics. For acute cases there is
no hope. For the _chronic_ a clean, dry, comfortable pen, well
disinfected, and a moderate diet of varied and laxative food are
essential. Wheat, bran or middlings, with corn, oat, barley or linseed
meal may be allowed in form of a mash. A little green vegetable food may
be added. Medicinal agents may be used to meet special indications, but
when a whole herd must be treated at once, antiseptics and febrifuges
have apparently proved the most generally helpful. The Bureau of Animal
Industry especially recommends the following: Wood charcoal, sulphur,
sodium sulphate and antimony sulphide, of each 1 lb.; sodium chloride,
bicarbonate and hyposulphite, of each 2 lbs.; mix thoroughly and add to
each feed in ratio with the size of the patient. In suitable cases, this
is said to improve the appetite and contribute much to convalescence.
Modifications will readily suggest themselves to meet individual
conditions and different stages of the disease—antithermics, eliminants,
calmatives. stimulants, tonics, etc.
_Serum Therapy._ This has been especially exploited and advocated in
America by De Schweinitz of the Bureau of Animal Industry, and Dr.
Peters of Lincoln, Neb. In Europe, Perroncito has prepared an antitoxin.
The serum is produced in the body of the cow or other animal which is
inoculated repeatedly with gradually encreasing doses of living hog
cholera cultures and with solutions of the bacilli and their products,
for a period of eight months, or until no reaction takes place from
large doses, and the blood serum added to cultures of hog cholera
bacilli causes agglutination of the latter. The serum is further tested
as to its power of preserving Guinea pigs inoculated with a lethal dose
of live hog cholera cultures. After separation from the blood the serum
is concentrated until it reaches a standard at which 10cc. proves
curative to a pig of 40 to 60 lbs. weight.
It proves most successful in animals in which the subacute or chronic
form of the disease has just begun. One injection only was given to each
animal. Of 1923 cases treated (1897–8) 30 per cent. died, and 70 per
cent. recovered. Of 3197 in abandoned herds (checks), 81.24 per cent.
were lost. (De Schweinitz.)
One drawback was found in the short period of immunity secured, the
susceptibility reappearing as soon as the antitoxin had been eliminated
from the body. This was met in part by using sterilized cultures
(toxins) along with the serum.
Another desideratum was a speedy means of distinguishing in field work
between hog cholera and swine plague, as the antitoxin of the one was
not protective against the other. To meet this, serum was obtained from
an animal immunized to both diseases, or a mixture was made of the sera
of two animals respectively made resistant to the two affections.
De Schweinitz was very optimistic in the matter, claiming that the serum
is absolutely harmless, can be used on pigs freely, and will cost but 15
cents for each animal. He estimated that of the $15,000,000 per annum
lost by Hog Cholera and Swine Plague in Iowa alone, $11,000,000 can be
saved at a comparatively small cost.
The method is scientifically sound in availing of the defensive products
of the immunized system for imparting to the animal attacked, the power
of vital resistance, and after allowing for enthusiasm, for the
inevitable mistakes, when used on a large scale, of other deadly swine
diseases for hog cholera, for the many accidents incident to its
application by operators who are not specially trained like the employés
of the Bureau, for its demand for acute and deadly outbreaks, as well as
for chronic and mild ones, and taking into account that in other hands
it has not fully borne out the promise made for it; yet it seems to have
some measure of merit, and where no systematic attempt is made by the
authorities for the extinction of the disease and its germ, it is an
available resort for the owner of herds.
The fundamental objection is that it entails the preservation, encrease
and spread of the poison, and like all temporizing measures, stands as a
barrier to the complete extinction of the plague. Giving such a very
transient protection, its repetition may be demanded in a few months or
a year, and proceeding on the ground that the pest must continue for all
time, the apparent economy of the process will prove, in the long run,
but a permanent and grievous tax.
The soundest and only truly economical course in dealing with this and
other deadly infections of swine is the radical extinction of the germ.
When the people can be educated up to this we shall see the dawn of a
brilliant future for our animal industries. Until then we must be
satisfied to fall back upon, and make the best use of the temporizing
measures now in vogue or that may hereafter be devised. Even if it
should be shown that hog cholera is at long intervals developed from a
‘sport’ of the usually harmless bacillus coli commune, the fact remains
that its great extensions and the resulting fatality are due to the
contagion alone, so that extinction remains the true watchword of
success and economy.