ANTHRAX.

Definition. Synonyms. History and geographical distribution. Etiology:

Bacillus anthracis. Susceptible animals: small rodents, sheep, horse,

camel, ox, goat, deer, stag, man, swine, dog, white rat and bird when

chilled, frog when heated; young most susceptible, races long exposed

to infection are least. Soils, wet, dense, impermeable, basins,

swamps, rich river bottoms, deltas, rich meadows, below tanneries,

alkaline soils, wells with surface drainage; season: wet, hot and dry,

late summer and autumn; flies; infected buildings, harness, vehicles,

fodder, litter, butchers’ knives and wagons, surgical instruments;

insolation; privation of water: plethora, starvation: overwork,

exhaustion. Bacillus anthracis: rod, nonmotile, 5 to 20μ by 1 to 1.5μ,

square ends, isolated in blood, often filamentous in cultures,

sporogenous, ærobic, stains easily in aniline and iodine, killed at

131° F. (spores at 203° to 282° F.), action under chemical

disinfectants, or septic ferments: air favors sporulation and

survival; in shallow graves, water. Infection atria: ingestion,

inhalation, inoculation, insects, placenta. Forms: fulminant,

internal, febrile, local,—external,—gloss-anthrax, pharyngeal,

hæmorrhoidal, subcutaneous. Lesions: blood normal in fulminant, dark,

diffluent, crenated or disintegrated globules in prolonged cases,

tissues brown or yellow, heart pale; liver enlarged, softened, pale,

hæmorrhagic: spleen enlarged, blood-gorged, ruptured; lymph glands

hyperæmic; serosæ congested, petechiated, hemorrhagic; lesions embolic

and like the blood swarm with bacilli. Toxins, ptomaines. Incubation 1

to 6 days. Symptoms: _internal cases_: hyperthermia, constitutional

disorder, mucosæ dusky, brownish, yellowish, bleeds, bloody urine,

rectal mucosa congested, blackish, colics, pharyngeal anthrax, blood

diffluent, black, broken down red globules, bacilli, abortions, death

in 12 to 48 hours: fulminant cases in cattle and sheep. Local

(external) anthrax, cutaneous, swellings: gloss-anthrax; pharyngeal,

hæmorrhoidal; sheep and goats; horse; swine; dogs; cats; birds.

Differential diagnosis: deductions from symptoms, condition of blood,

animals attacked, environment or conditions of life, presence of the

bacillus. Examination for bacillus. Post mortem lesions; gelatinoid,

bloody exudate, petechiæ, blood-gorged spleen, lymph glands, and

liver, diffluent blood, bacilli in capillaries. Inoculation

intravenously. Cultures. Prognosis. Mortality often 70 per cent.

_Definition._ Anthrax is an acute infectious bacteridian disease

occurring casually in the herbivora and omnivora and, under favorable

conditions, communicable to carnivora, birds and batrachians. Its

special features are the presence of the _bacillus anthracis_ in the

diseased parts, the destruction of red globules, the arrest of

hæmatosis, the occurrence of capillary embolism, extravasations and

exudations, and of necrotic processes in the affected parts, and a

sanguineous engorgement of the spleen.

_Synonyms._ Malignant pustule; Splenic apoplexy; Splenic Fever; Charbon;

Miltzbrand; Woolsorter’s Disease; Malignant Carbuncle; Contagious

Carbuncle.

_History and Geographical Distribution._ As anthrax prevails in damp,

undrained lands where agriculture is backward, it is not wonderful that

it can be traced to near the dawn of human history when the whole race

lived under primitive conditions. Moses records its ravages on the

bottom lands of the Nile (Ex. ix. 9), Homer, on the plains of Troy

(Iliad, Bk. 1st), Ovid, Plutarch, Dionysius, Livy, Lucretia, Columella,

Virgil, Pliny and the Arabian physicians all show a familiarity with a

disease of this nature. Later, Heusinger collects evidence of its

prevalence in certain areas in all parts of the world from the equator

to the Arctic circle. The mortality was often very high, thus Kirchner

records the death of 60,000 people in a single epidemic in 1617, in the

vicinity of Naples, Placide-Justin, that of 15,000 in St. Domingo in six

weeks in 1770, and on the Russian and Siberian Steppes it is not

uncommon for hundreds of thousands of domestic animals and thousands of

human beings to suffer in a single year.

The geographical distribution of the disease is largely influenced by

soil and climate. On dense, impermeable clays and hardpan subsoils, on

river bottom lands, dried lake basins and deltas, rich in organic

matter, and with the air driven out by water or gaseous fermentation

products, the germ is preserved and propagated if once introduced. Thus

it is common around the mouth of the Nile, and along the occasionally

inundated banks of the Vistula and Danube, the Spree, Oder, Elbe, Rhine,

Eure, Loire, Seine and Marne, and in England in the Fen district. On the

rich, undrained, black soils of Siberia it is extremely prevalent and

fatal. In the rich Genesee Valley, N. Y., the writer has seen 200 cattle

in one herd and three human attendants attacked in the course of a

fortnight, and in different meadows receiving the drainage of tanneries,

the affection prevails every summer and autumn. It is much more

prevalent in the rich lands of the Southern States and a widespread and

deadly epizoötic prevailed in Louisiana in 1896. Where the soil is

favorable, the germ may be preserved indefinitely, even in mountainous

districts, and near Los Angeles, Cal., where the disease was introduced

in imported sheep some years ago it has become permanently domiciled, on

the dry ranges which have moist lands (Cienegas). When an outbreak

occurs, the herds or flocks are usually moved to higher soil, and the

carcasses being left unburned and unburied the infection is spreading

year by year (McGowan, Morrison).

_Etiology._ Nothing is more certain than that the disease is due to the

introduction into the blood or tissues of the bacillus anthracis or its

spores. These microbes are always found in the anthrax lesions and in

the blood of the victim in the advanced stages. When grown in bouillon

cultures to the hundredth generation they retain their virulence

unabridged and determine the same lesions in the animals inoculated.

When the infecting culture has been passed through a Pasteur filter the

virulence is lost with the removal of the bacilli. The fresh anthrax

blood containing bacilli but no spores when subjected to compressed

oxygen (50 atmospheres) becomes noninfecting. The same liquid when

boiled proves non-virulent.

Certain conditions, however, contribute to the propagation and reception

of the bacillus and these may be considered as accessory causes.

_Animals susceptible._ The receptivity of the animal exposed is of first

importance. Young animals are the most susceptible. The small rodents,

the mouse, Guinea pig and rabbit are susceptible in the order named,

followed by the sheep and horse and these again by the camel and ox.

Among the wild herbivora the goat, deer and stag have a high

susceptibility. Man is less susceptible yet contracts the disease

readily by inoculation, inhalation or ingestion. Swine and dogs are

comparatively little susceptible, yet they often contract the disease by

eating the carcasses or discharges of anthrax animals. White rats and

birds are held to be insusceptible, yet the latter contract the disease

readily when the vitality of the system has been reduced by immersing

the body in water, or giving antipyrine. A similar result is observed in

the otherwise immune frog if the body is heated above the normal cold

blooded temperature. The receptivity may vary, however, in the same

genus and species. The Algerian sheep is virtually immune from anthrax,

perhaps because its ancestors have been so constantly exposed that only

the insusceptible strains survived. Swine, birds and carnivora may have

similarly acquired a fair measure of immunity by the survival of the

fittest. Apart from this, however, a flesh diet is to a certain extent

protective, thus Feser’s rats if fed vegetable food proved susceptible

to inoculated anthrax, while if fed on animal food they were

comparatively immune.

The animal that has survived an attack of anthrax is thereafter strongly

immune. This serves to partly explain the apparent immunity of animals

bred in an anthrax district, the young animal becoming habituated to

infinitesimal doses of the toxins, conveyed in the secretions of the

uterine glands or mammæ.

_Soil_ is a factor so far as it preserves and propagates the bacillus.

As already stated, soils that are naturally wet by reason of their

impermeable character, their position on or near the water level, their

conformation in basins which dry out in late summer or autumn, are

especially favorable to preservation of the bacillus. Again soils that

are specially rich by reason of an excess of decomposing vegetable and

animal remains, or because of excessive manuring, tend to preserve and

multiply the microbe. Rich, flat meadows below tanneries or abattoirs,

and irrigated from these or occasionally overflowed are especially

dangerous to stock placed upon them. Soils with an alkaline reaction

from the lime, potash or ammonia present are very favorable to anthrax.

Wells receiving surface drainage are common factors in carrying

infection.

_Season_ is a contributing factor in various ways. Damp seasons

sometimes bring the germ to the surface of the soil by the gradual

elevation of the water level, or by causing inundations and the

deposition of the bacillus on areas of pasture or forage that were

previously free, or finally by bringing the earth worms to the surface

and leading to the deposition in their casts of the bacillus brought

from the infected graves or retentive subsoils. Dry seasons are,

however, the anthrax seasons _par excellence_, as they dry up swamps,

fens, ponds, lakes, basins, deltas and bottom lands, and render them

available for pasture. The germladen mud of these drying lands is also

raised in dust and deposited on the vegetation to be taken in by the

animals. Again on the drying basins and bottom lands the tempting green

vegetation is often pulled up by the roots with adherent, infecting mud.

For the above reasons, even in an anthrax region the malady is most

prevalent in the late summer and fall, and in certain valleys like those

of Corsica the stock is considered safe until the dry autumn weather

demands their removal to the mountains.

Another reason for the summer epizoötics is found in the transference of

the germ by flies. House _flies_, horse-flies, blowflies, mosquitoes,

etc., carry the bacillus on their feet, mandibles or piercing apparatus,

and even in their stomachs (Bollinger) and transfer it from one

individual to another. It is worthy of note that the great majority of

cases of local anthrax in man occur on the habitually uncovered parts of

the body (face, neck, hands and arms) and start from a centre like the

bite of an insect.

_Stables_, _stable utensils_, _harness_, _shafts_, _poles_, _fodder_ and

_litter_ are familiar bearers of the virus. Butchers’ knives and wagons

and surgical instruments are further media of contagion.

Certain conditions of the animal system expose it to attack. The fever

and constitutional disturbance which are caused by _the extreme heats of

summer and autumn_ are strongly predisposing, especially if alternated

with frigid nights as seen on the Siberian Steppes. _Privation of water_

raises animal temperature and thus the _drying up of the customary

drinking places_ becomes an important factor. _Plethora_ and

_starvation_ are alike predisposing, probably by lessening the resisting

power of the system. _Overwork_ and _exhaustion_ predispose, as Roger

showed by making the immune white rat turn a wheel until worn out and

then successfully inoculating it. The addition of lactic acid to the

virulent liquid (1:500) greatly encreases its potency (Arloing, Cornevin

and Thomas) and the further addition of fermentescible sugar and rest

enhances this still more (Kitt). The production of lactic acid by

muscular overexertion is thus a potent accessory cause in fatigue.

_Bacillus anthracis._ This was first demonstrated in anthrax blood and

exudates by Pollender and Brauel in 1849 and 1850 but as they failed to

find it in all cases they concluded that it was not the essential cause.

Davaine who found the bacilli in 1850 suspected that they were

pathogenic and by 1863 he had shown that blood which contained no

bacilli was non-virulent, while that in which these organisms were

present was constantly infecting. Klebs and Tiegel in 1871 filtered

anthrax blood through an earthenware vase and found that the clear

filtrate (bacillus-free) was noninfecting.

The _bacillus anthracis_ as found in the blood is a nonmotile rod-shaped

organism, 5 to 20μ long by 1 to 1.5μ broad with ends apparently square,

but really slightly cup shaped as seen in the stained specimens when two

have remained connected end to end. Under favorable conditions a clear

hyaline envelope may be seen around the bacillus. Though usually

isolated in the living blood, yet in bouillon cultures the bacilli grow

out into long flexible filaments, made up of separate segments which are

easily distinguished in the stained specimen. In all cultures out of the

living animal body, in the presence of air and at a suitable temperature

spores form endogenously in the bacilli and are set free by the granular

degeneration of the latter. In peptonized bouillon this may occur in

four days at 14° C., or in eight hours at 37° to 40° C., but not above

42° C. (Schreiber. Centr. S. Bact. 1896). Sporulation never occurs in

the living animal body.

The bacillus is ærobic, yet it will grow at the bottom of a stick

culture in solid media. It fails to grow in an atmosphere of CO_{2}, H,

or N. It stains readily in aniline colors, and also by Gram’s method. It

grows freely on a variety of culture media (blood serum, aqueous humor,

urine, vegetable infusions, milk, meat bouillon, peptonized gelatine,

potatoes, etc.) at a temperature of 20° to 38° C. Growth ceases below

12° C., and above 45° C. Growth is most active in neutral or slightly

alkaline media, and is arrested by that which is decidedly acid.

_Action of physical and chemical agents on the bacillus anthracis._ The

bacilli survive a temperature of −45° C. (−49° F.), but they perish in

10 minutes at a temperature of 100° C. (212° F). A temperature of 55° C.

(131° F.), proves fatal if sufficiently prolonged. The spores are much

more resistant. They have survived −130° C. (−202° F.) and though they

may die in 10 minutes in liquid media kept at 95° C. (203° F.), yet when

old and dry it may require several hours at 140° C. (282° F.) to

sterilize them.

Even the bacilli are comparatively resistant to ordinary disinfectants,

and, as spores form in the body very rapidly after death, and in

virulent products, it is always best to assume their presence. In a

moist medium Cl. 44.7% destroyed the spores in 3 hours: HCl (1:1100) in

2 hours: HgCl (1:1000) in a few minutes: HgI_{2} (1:20000) in 2 hours:

Malachite green (1:40,000) in 2 hours: Methyl violet (1:5000) in 2

hours: Aseptol (1:10) in 10 minutes: Carbolic acid (4:100) with HCl

(2:100) in 1 hour.

_Action of septic ferments on the bacillus anthracis._ Rapid

putrefaction in the anthrax carcass which has not been opened tends to

speedy granular degeneration and death of the bacillus anthracis, so

that the blood and tissues may be no longer infecting after six days in

summer. In such cases the irrespirable gaseous products of decomposition

drive out the oxygen without which the bacillus cannot live. If,

however, spores have already formed or if air is freely admitted the

infection survives in spite of decomposition. The search for the bacilli

may thus be fruitless as soon as decomposition is well advanced and the

material can only be virulent through any spores that may have formed.

Eventration serves to retard sepsis and admit air to form spores, and

salting operates in a similar manner.

The infected hides, the nasal, buccal, kidney and bowel discharges, and

spilt blood and exudates mingling freely with the air tend to form

spores and to preserve and propagate the contagion. On the contrary

prompt and deep burial, without opening the carcass and before spores

can have formed will usually ensure its destruction. The main danger in

such cases comes from infecting matter (adherent to the surface of the

body) which sporulates easily. This serves to explain the great danger

of working in anthrax hides, leather, horn, wool, hairs and bristles. It

also explains sporulation and preservation of infection when the

virulent excretions, blood, etc., mix with the surface layers of soil.

This may happen at a greater depth (3 or 4 feet) in a very porous soil

and where the temperature is sufficiently elevated (above 14° C.) It may

even occur in water. The dried spores are mostly carried in dust, hay,

fodder, and running streams.

Since 1892 anthrax has prevailed along the banks of the Delaware river

for a distance of 40 miles in N. J. and Del., destroying from 70 to 80

per cent of the farm stock. The great morocco industry on this river

draws infected hides from India, China, Russia, Africa and South

America, and the spores are carried and distributed by the tides.

_Infection-Atria._ Infection may occur by a variety of channels as: 1st,

by _ingestion_, giving rise most commonly to anthrax of the mouth,

throat or intestines; 2d, by _inhalation_, giving rise to pulmonary

anthrax (wool-sorter’s disease): 3d, by _inoculation_ through contact of

abrasions, wounds, etc., with infecting bodies, including surgical

instruments: 4th, by flies and other insects: and 5th, by transmission

to the fœtus in utero. This last form is very rare in the larger

animals, but has been repeatedly seen in Guinea pigs, rabbits, goats and

even in one case (Pangalli) in man.

_Forms of Anthrax in Domestic Animals._ In the lower animals anthrax

manifests itself differently according to the seat of invasion and the

amount of the virus. The worst forms, seen especially in cattle and

sheep, are so sudden that they have been called _apoplectic_ or

_fulminant_. Without premonitory symptoms there is sudden loss of

appetite, trembling, haggard expression of face, uneasy shifting of the

feet, irregular movements backward or to one side, dyspnœa, cyanosis,

plaintive cries, convulsions, ejection of blood by the nose or with

urine or fæces, and death in a time varying from a few minutes to four

hours. The second type is the _anthrax fever_, known also as _splenic

fever_, _splenic apoplexy_, or _internal anthrax_. In this form there

may be prodromata, especially in sheep, excitability, restlessness, and

above all, a rise of temperature of often 3° or 4°. There may be

distillation of drops of blood from the nose, eyes or ears, the mucosæ

become congested, and in sheep this may show on the finer parts of the

skin, as inside the forearm or thigh. Tremors, erection of the hairs,

dulness, prostration, lagging behind the flock or herd, insensibility of

the loins to pinching, inappetence, ardent thirst, grinding of the

teeth, colics, tympany, mucus coated, bloody or liquid fæces, bloody

urine, tumultuous heart beats, dyspnœa, dark, congested mucosæ,

amounting to cyanosis, and spasmodic contractions of the muscles of the

back, neck or eyes. If blood is drawn it may appear abnormally dark in

color and very slow to brighten under the action of the air, it may have

a thick, tarry appearance, and form a very loose clot. Death, (usually

in coma or convulsions) will supervene, in sheep under 24 hours, in

cattle in 2 to 5 days, and in horses in 1 to 6 days. The third type is

the _local_ or _external anthrax_, assuming in cattle the special forms

of _gloss-anthrax_, _pharyngeal anthrax_, _hœmorrhoidal anthrax_,

_cutaneous_ and _subcutaneous anthrax_. In horses most of the same forms

appear, in the tongue, throat, neck, shoulders, withers, flank or thigh.

These swellings have a firm or doughy feeling, are comparatively and

sometimes wholly insensible and show a marked tendency to necrotic

changes. When incised they show extensive blood extravasation, or a

pale, straw-colored exudate mixed with sanguineous lines or patches, and

manifest no tendency to suppuration, nor to emphysematous crepitation.

These features distinguish them from phlegmon and emphysematous anthrax.

When suppuration ensues it is tardy and indolent and is, on the whole, a

favorable indication. In all cases the bacillus may be found on

microscopic examination of the exudate.

_Lesions._ Putrefaction of the carcass is usually rapid. In the very

rapidly fatal cases the changes in the blood and tissues are often

little marked, and after the removal of the enlarged, engorged spleen

and infiltrated internal organs, the carcass might often be placed on

the market without much suspicion. In more prolonged cases the blood is

profoundly changed, being very dark, not subject to rapid æration, and

incapable of coagulating firmly or at all. The red globules are crenated

or otherwise distorted, adhere to each other in irregular masses, and

have parted with much of their hæmoglobin which diffused in the serum

stains the intima of the blood vessels and other white tissues. The

leucocytes are relatively very much encreased. The bacteria are easily

found in the intervals between the globules. The heart is often soft,

discolored, as it were parboiled, with the endocardium deeply stained

and the contained blood dark and diffluent or liquid. The liver is

usually enlarged, softened, friable, and as if parboiled, with many

hæmorrhagic patches. The spleen is materially, often enormously

enlarged, irregular in outline from extreme engorgement with blood, and

in exceptional cases even ruptured. An encrease to two or three times

the normal is common. The bacilli are present in great numbers in the

spleen, alike in the pulp, in the blood vessels and in the trabeculæ.

The lymph glands are almost always hyperæmic, hypertrophied, and

softened, especially in the vicinity of the localizations of the tissue

lesions. They may be merely petechiated, or they may seem like a mass of

black blood, and under pressure may break down readily into a

sanguineous pulpy mass. Like the spleen they are favorite centres for

the accumulation of the bacilli. The marked alterations in these glands

will often indicate the channel by which the infection entered the body.

The serosæ are usually hyperæmic, with many hæmorrhagic points and even

extensive exudations, and they often enclose a sanguineous liquid. The

hyperæmia and points or patches of extravasation are to be found in any

part of the body in which the bacilli have been colonized, thus they are

common in the tongue, the throat, the lungs, the stomach or bowels, the

mesentery, the omentum, the skin, the connective tissue, or the muscular

system. There may be bloody or gelatinoid exudation, but there are

always the capillary embolisms by irregular masses of blood globules,

and bacilli. These embolisms, the arrest of hæmatosis and the

destructive action of the toxins on the red globules go far to account

for the extreme fatality of the disease.

_Morbid poisons._ Hoffa found in anthrax cultures a ptomain which killed

with anthrax symptoms. Hankin obtained a deadly albumose which in small

doses procured immunity. Brieger and Fraënkel separated a toxalbumin,

and Martin too, a protalbumose and a deuteralbumose together with a

ptomain. Marmier separated a toxin which did not give the reactions of

the albuminoids, albumoses, peptones nor alkaloids. This was not

poisonous in small doses, to animals possessing immunity—natural or

artificial. It was weakened but not destroyed by 110° C., and was

rendered harmless by treatment with alkaline hypochlorites. Immunity

could be induced by its use in small non-fatal doses. This is present in

the bacilli and being soluble in water can be secured from these by

diffusion in watery fluids and especially so if aided by heat.

_Incubation._ The implanted bacillus begins at once to multiply in the

tissues, but the encrease is at first slow and the resulting morbid

phenomena slight, so that there appears to be a period of incubation. In

experimental inoculations in which this can be certainly noted it

extends from one to two and even three days in the rabbit and Guinea

pig, from two to four days in sheep, and from three to six days in

horses and cattle. It may be shortened by giving an overdose and

especially if this is introduced intravenously, the chemical poisons

apparently acting at once. In young animals, too, the period is

shortened, unless they have been rendered refractory by a milk diet or

otherwise.

_Symptoms._ These vary according to the species affected, and the seat

of the disease, general or local, _internal_ or _external_. In the

latter case the febrile and constitutional disturbance is delayed. In

the _internal_ cases the fever is early and of a high type. Even before

the animal appears to be seriously ill, while still keeping with the

herd and showing life and vigor, there may be high temperature, 104° to

106° F., pulse and breathing accelerated, heart beats tumultuous,

tremors or shivering or perhaps only staring coat, anorexia, and

grinding of the teeth. Later there may be drooping head and ears,

dulness, a disposition to lie, apathy, stupor and somnolence. Nervous

excitement and delirium have been noticed. The patient becomes weak,

especially behind, comatose, and the temperature declines to, it may be,

97° or even 94° F., prior to death. The visible mucosæ becomes dusky,

brownish or yellowish, and streaks of blood may appear in the nose or

elsewhere. The urine may be red, the fæces covered with mucus, or blood

streaked, and the rectal mucosa of a violet tinge, or blackish and blood

gorged. In this the vulvar mucosa often participates. Local swellings

may appear in the tongue or pharynx, even if not on the surface, or

colics indicate implication of the digestive organs. The examination of

the blood early reveals the presence of the bacillus, and as the disease

advances, its black, incoagulable, tarry, or coffee-grounds appearance

becomes characteristic. Pregnant animals are liable to abort. Death

occurs in 12 to 48 hours. Most cases are fatal at the beginning of an

outbreak, while later the great majority often recover.

_Fulminant cases_ (Anthrax acutissimus) occur mostly in cattle or sheep,

in high condition, the victim being found dead in pasture or stall,

without previous observation of illness, or, if seen during life there

is the sudden attack, leaving food, muscular tremors, anxious expression

of countenance, hyperthermia, dyspnœa, dark red mucosæ, it may be

streaks of blood on them, plaintive cries, rolling of the eyes, spasms

or coma, and death in a few minutes to one or two hours. In _sheep_

there may be separation from the flock, pawing, stretching, shaking of

head, turning in circle, dyspnœa, falling, convulsive struggling,

passing of blood by nose, kidneys or bowels and death.

_Local Anthrax in Cattle. Symptoms._ In _cutaneous anthrax_ the

circumscribed swellings appear suddenly, and may grow to considerable

dimensions on different parts of the skin, head, neck, breast,

shoulders, abdomen, axilla, sheath, udder, or flanks. There may be one

or many, and they lack the acute early tenderness, and later crepitation

of black quarter. On white skins they are dark red, or violet, and when

incised, show a gelatinoid, bloody, non-suppurating mass, abounding in

bacilli.

_Gloss-anthrax_ implicates the whole, or it may be the roots only, of

the tongue and the fauces. There is profuse salivation, perhaps bloody,

intermaxillary and pharyngeal swelling, anorexia, and the tongue is

found protruding, swollen, violaceous, vesiculated or with rounded

nodules, or sloughs and ulcers, with lardaceous or blood stained

bottoms. Hyperthermia and constitutional symptoms are present.

_Pharyngeal anthrax_ is manifested by swelling of the throat, profuse

salivation more or less marked with blood, complete dysphagia, attending

on the marked febrile and constitutional symptoms already described.

_Hæmorrhoidal anthrax_, a common complication of the constitutional

disease, is manifested by infiltration, blood extravasation, violet

discoloration and often enormous swelling of the rectal mucosa, seen

mainly during straining, but sometimes also as a constant protrusion.

=Local Anthrax in Sheep and Goats.= External anthrax swellings may form

on the face, throat or udder with the general characters of those of the

ox, but this form is much more rare than in cattle and horses. The usual

form is the internal one, with engorgement of spleen, liver, and perhaps

some other internal organ, and it is relatively very fatal.

=Local Anthrax in the Horse.= _Symptoms._ In anthrax districts, tumors

form in the seats of inoculations on sores, insect bites, or sometimes

without apparent local cause, as a result perhaps of a general

infection. The infiltration takes place suddenly into or beneath the

cutis, mostly on the head, tongue, throat, neck, breast, shoulder,

inguinal region, mammæ, croup, or thigh, encreases rapidly, but without

crepitation, or suppuration, the incision showing the general characters

described in the ox, and early attended by the constitutional disorder.

The general fever is often later in developing, less intense, and, on

the whole, less fatal than the purely internal forms.

=Anthrax in Swine.= _Symptoms._ Swine are, on the whole, less

susceptible than cattle, and on the strength of his laboratory

experiments Pasteur denied their susceptibility. The mistake gained

a wide acceptance, yet experienced practitioners knew that they were

occasionally infected by eating the carcasses or droppings of

anthrax cattle. I had seen a number of swine die in common with

cattle in an outbreak at Swineshead, Lincolnshire, in 1863, and a

like occurrence took place in East Lothian, and similar cases are

reported by McFadyean, Trombitas and Von Ratz, while Crookshank and

Perroncito have respectively inoculated the pig with success. In my

experience at East Lothian a shepherd skinned an anthrax bullock and

then castrated several litters of pigs, all of which died of

anthrax. Much doubtless depends on the condition of the animal as

regards food (flesh or vegetable), the presence of lactic or other

organic acid, the coincidence of infection with anthrax bacillus and

one of those conditions, which habitually enhances its virulence.

There may be named venesection (Rodet) or its counterpart anæmia,

the presence in the blood of inert powders—precipitates (Bardach),

fatigue—sarco-lactic acid (Charrin and Roger), starvation—dyspepsia

(Canalis and Morpurgo), privation of water (Pernice and Alessi), the

products of previous or coincident illness (Galtier).

The pig, infected by ingestion, suffers especially from pharyngeal and

intestinal anthrax. There is marked swelling of the throat with

stiffness, dysphagia, champing of the jaws, salivation, frothing about

the lips tinged with blood, dark, violet discoloration or ulceration of

the fauces and tonsils, retching, vomiting, hoarseness of grunt,

extension of the swelling to the face, with petechial spots and patches,

diarrhœa with frothy or bloody fæces, great muscular weakness, a

disposition to lie, it may be actual paraplegia, with the usual

accompaniments of hyperthermia, constitutional disorder, cyanosed, or

dusky brown, reddish or yellowish mucosæ, and the black, incoagulable

blood, with destruction of the red globules.

=Anthrax in Dogs.= _Symptoms._ In the outbreak at Swineshead,

Lincolnshire, in which the pigs suffered, one shepherd dog contracted

the disease from eating the carcasses. It took the pharyngeal and

intestinal form, with dysphagia, vomiting, bloody diarrhœa and high

fever. Straus found that young puppies were very susceptible and old

dogs refractory probably because of flesh diet and exposure. The

excision of the spleen encreased the susceptibility to 76 per cent.

instead of 20 per cent. (Bardach). Cornevin saw 5 dogs die the same

night out of 7 that ate from an anthrax carcass. Much depends on the

previous exposure and existing condition of the dog.

_Cats_ have been observed to suffer under similar conditions. At Geneseo

in 1877 I found that a cat and three young horses died from licking the

blood from a stoneboat on which an anthrax hide had been carried.

=Anthrax in Birds.= _Symptoms._ Birds (chickens) are naturally less

susceptible than swine, yet they succumb readily to inoculation, when

the body has been cooled by partial immersion in cold water. Caplewsky

found that, apart from artificial chilling, young pigeons of certain

breeds were easily infected, and Œmler successfully inoculated small

birds, sparrows, finches, canaries, yellow hammers, red breasts. The

larger birds are more resistant but succumb readily if dosed with

chloral hydrate, or antipyrin (Wagner). Birds of prey seem to be immune.

In chickens the disease is very acute, of rapid progress and fatal. A

few hours after inoculation they are seized with dulness, debility,

sunken head, drooping wings and tail, ruffled feathers, and dark red or

black discoloration of comb and wattles. Dark colored anthrax swellings

may appear on these last, on the eyes, tongue, palate or feet, and the

obstruction of breathing may cause general cyanosis. Weakness is

extreme, the bird staggers or is unable to rise, has violent tremors or

convulsions, with bloody diarrhœa and perishes after a few hours or a

day’s illness. The presence of anthrax in the locality, or in other

species, will be to some extent a safeguard against confounding chicken

cholera, entero-hepatitis or malignant œdema with this affection. The

crucial diagnosis is based, as in other animals on the discovery of the

characteristic bacillus.

_Differential Diagnosis._ The suddenness of the attack, hyperthermia,

dusky, cyanotic, petechiated mucosæ, the escape of blood from mucous

surfaces, the dark, tarry blood, brightening imperfectly on exposure to

the air, its comparatively loose coagulum, the crenation and destruction

of red globules, the staining of the serum with hæmatoidin, the

leucocytosis, the engorged, enlarged liver and spleen, and the

gelatinoid or bloody swellings, not gasogenic as in blackquarter or

malignant œdema, together present a picture which is strongly suggestive

of anthrax. If the malady affects domestic animals generally, is

especially virulent in cattle, sheep and horses, and attacks even man;

if the district is subject to anthrax, or of a rich damp soil which

would be favorable to the preservation of bacillus anthracis; if it is

in the line of watershed from stock markets, abattoirs, tanneries,

rendering works, glue factories, packing houses, sausage factories, or

phosphate works; if forage or new stock has been introduced from an

anthrax district; and if the outbreak has taken place with a high water

level, or during a dry hot season the case for anthrax will be

strengthened.

The final tests are, however, by the microscope and inoculation. To

discover the bacillus a power of 400 to 500 diameters is desirable. From

the living animal take a drop of blood, exudate, or hæmorrhagic

extravasation, make a thin film on a cover glass by drawing across it

the straight edge of another one, dry the film, then pass it three times

through the alcohol flame film downward, stain in anilin dies, or clear

with acetic acid and examine. The bacillus is large (5 to 20µ by 1 to

1.5µ), nonmotile, of uniform thickness throughout, and sharply cut off

at the ends. The bacillus of blackquarter is shorter, often club-shaped

because of a spore in one end, has rounded ends, is flagellate, motile

and gasogenic. That of malignant œdema is much thinner, has rounded

ends, sluggish movements and is gasogenic. The bacillus subtilis (hay

bacillus), is short, thick, with rounded ends each bearing a flagellum

and is motile. The proteus vulgaris (common septic saprophyte) is small,

short, with rounded ends, and very active movements. If the subject is

dead we may examine the blood, or the scraping from the cut surface of

the spleen, liver, kidney, congested lymph gland or other part bearing

the lesion.

If we find in the carcass exudates gelatinoid or bloody (especially the

latter), petechiæ, dark, uncoagulated blood, brightening little on

exposure, blood gorged spleen, congested or hæmorrhagic condition of one

or more internal organs, muscle or connective tissue, (particularly of

the lymph glands), if the muscles of the loins, quarters, thighs,

diaphragm or elsewhere, are soft, as if parboiled or salmon-colored,

clammy, friable, or if reddish, yellowish, brownish, with petechiæ, and

capillary embolism the case will require critical examination. If the

first examination fails to show the bacilli, repeat it from different

lesions until thoroughly satisfied of their absence, or until another

cause for the condition has been discovered. The blocking of the

capillaries with bacilli in the various lesions is a most important

point, never to be overlooked.

In case of uncertainty, inoculation of a Guinea pig, mouse or rabbit

should be made. The blood or scraping from the seat of a lesion is made

into an emulsion if necessary, and injected subcutem. A single bacillus

will destroy a mouse or Guinea pig in from one to four days, and the

blood shows the characteristic bacilli.

One must, however, exclude the possibility of septic bacteria, excluding

or obscuring the bacillus anthracis, by taking the inoculating material

from the blood of the living animal, or from the same or the tissues as

shortly after death as possible. Fifteen hours may be altogether too

late for inoculation. To exclude the anærobic bacteria of black quarter,

malignant œdema and septic affections, make an emulsion of the suspected

material in sterilized water, filter through a boiled cloth and inject a

strong dose into the auricular vein of a rabbit. The anærobic bacteria

perish in the blood and if anthrax bacilla are present they are found in

pure cultures.

In inoculating suspected water or infusion of forage the intravenous

method should be adopted.

Another resort is to make two artificial cultures, one in free air, and

the other in an atmosphere of nitrogen or carbon dioxide. The bacillus

anthracis develops in the first, the anærobes in the second.

_Prognosis. Mortality._ Fulminant cases are uniformly fatal. _Acute

intestinal_ cases are usually fatal in 70 to 90 per cent. of the

subjects at the beginning of an outbreak. Toward the decline most cases

may recover. In a herd of 200 head, at Avon, N. Y. in 1875, 40 fat

bullocks died in two weeks, and 50 more showed a marked hyperthermia,

yet under a change of pasture, and antiseptics, all but two of the

latter recovered. As serving to identify the disease, three attendants

suffered from malignant vesicle, but recovered.