Chapter IX: Front Matter (9)

_Prevention._ This is most effectively secured by sanitation of the soil and buildings. Thorough drainage to secure perfect and constant æration leads to destruction of the anærobic germ, or the suspension of its pathogenic quality. Thorough culture contributes largely to this sanitary æration, while baking of the surface counteracts it. When thorough drainage is impossible it may be desirable to subject the land to gardening or to the production of crops that are to be used for human consumption and not for domestic animals. Kitt’s suggestion, to soil cattle on hay, produced on such lands, and to exclude from the infected lands all animals that by wounds or sores near the feet, or by raw gums from shedding of teeth, furnish infection atria for the poison, is insufficient, as stalled cattle occasionally suffer.

When an open porous soil maintains the infection by reason of the presence of an excess of decomposing organic matter, that may be largely remedied by a free application of quick lime. This hastens the decomposition of the organic matter and after a year or two, when that has been largely disposed of, the good effects may be expected.

An important measure is to exclude from fairs, markets, and above all from clay or other dense wet soils into which they might convey the germs, all animals brought from infected soils.

Disinfection of the buildings where diseased and infected animals have been is an essential measure. Wells and streams receiving the drainage of infected lands must be carefully avoided.

Diseased animals must be carefully isolated, and all their droppings, and products of every kind disinfected.

The carcasses are best cremated or rendered under superheated steam under pressure. Solution in sulphuric acid may be employed. If none of these are available they may be deeply buried in dry porous soil well apart from any risk of drainage into wells or water supplies. The area occupied by the graves should be fenced in so that no cattle nor sheep can gain access to it, and any vegetation grown on the graves should be burned. The danger of the germs being raised to the surface by soil water or earth worms must be recognized and any consequent evil guarded against. The carcass should not be cut open but buried in the hide, or if the latter is preserved it should be treated with a chloride of lime solution. If a carcass is opened for scientific purposes, great care must be taken to avoid the distribution of the bacillus in soil appropriate to its preservation. The meat should not be preserved for human consumption unless it has been cooked under pressure at a temperature of 240° F. The object is not to destroy any poison which would be fatal to man, but rather to prevent the spread of the spores on new soil and the extension of the area of infection.

The reduction or prevention of sudden plethora was formerly availed of to lessen the number of victims and it is well to still bear in mind that this has an appreciable though limited effect. As a means of reducing plethora a free bleeding was resorted to when the period of yearly prevalence approached, and no less when the disease had already appeared in a herd. I can mention an instance in which infection was carried on the fleam from the first animal bled (the sick one) and caused the fatal infected swelling around the phlebotomy wound in the next seven animals operated on. Another objection to phlebotomy is the tendency to a rapid reproduction of blood, which the depletion brings about, and the supervention of a greater danger than before, in the course of a month or more. Purgatives and diuretics are somewhat less objectionable in this sense. Careful feeding to keep the animal constantly in good condition does something to obviate sudden plethora and its attendant dangers, and thus an allowance of grain or linseed cake through winter and early spring, or when the pastures are bare, will bring the animals through in fine condition, and ward off the danger that comes from a sudden access of rich aliment.

Another measure was the insertion of a seton in the dewlap. The theory was to counteract plethora but the benefit probably came rather from the formation of an actively granulating wound, which came in contact with the ground and received the bacillus, but in which the abundance of air, and of active leucocytes checked the propagation of the germ and the occurrence of a fatal infection. A certain grade of immunity was the natural result in many cases.

_Immunization._ As the first attack of emphysematous anthrax secures for the subject of it immunity against a second, we are furnished with a reasonable basis for the practice of artificial immunization. This has been attained by a variety of methods, the essential feature of each being the subjecting of the system of the animal to be treated, to the action of the toxins of the specific bacillus.

1st. A culture of the bacillus made in the thermostat at 42 C. (107.6° F.) so as to prevent the formation of spores is then sterilized by heating to 100° C. for one hour and then injected subcutem in a dose of 2 drams, to be repeated on the second day. This, like all the other methods named should be done by some one accustomed to bacteriological manipulation and the sterilization completed by superheating the neck of the vessel containing the mixture. Any germs escaping on the hands, instruments or other objects used will prove fatal in spite of all the appearance of precautions.

2d. Roux sterilized his cultures by filtering them through a porcelain (Pasteur) filter and using only the filtrate for injection. This requires even greater precaution in manipulation as what is left in the filter is most virulent, and must be thoroughly sterilized to obviate dangers from its dissemination.

3d. Intravenous injection of a small quantity of virus, containing but a few bacilli produces no local swelling, but only a slight temporary hyperthermia and permanent immunity. The greatest care is necessary in the manipulation, to prevent any contact of the bacillus with the subcutaneous tissues or the walls of the vein. The virulent exudate swarming with bacilli is taken and a drop or two added to a normal salt solution, which is diluted and shaken in a stoppered bottle, until each drop contains but one, or at most two bacilli. Then the hands having been thoroughly washed with soap and warm water and rinsed in a 5 per cent. solution of carbolic acid, and the instruments having been boiled, the vein is raised as for bleeding, and penetrated by a short cannula and trochar, which after boiling has been dipped in the carbolic acid solution, the trochar is withdrawn, and the nozzle of the syringe containing the virulent solution is inserted through the cannula, so that its point is free in the centre of the blood stream, into which a few drops of the virulent solution are discharged. The nozzle is left in place for a few seconds to ensure the washing of any infecting matter from its point, when it is withdrawn, followed immediately after by the cannula. Great care should be taken to avoid any scratching of the inner coat of the vein with the cannula, trochar or nozzle.

4th. Another method of immunizing is by the injection of the virulent liquid into the trachea and bronchia. This appears to bring it so directly in contact with the blood, that the microbes are destroyed as rapidly as if it were introduced into the blood stream direct. The injection is made between two tracheal rings, the manipulation being essentially the same as in the cases of the vein, the tissues being first perforated by a sterilized cannula and trochar, and the sterilized nozzle subsequently inserted through the cannula.

5th. Inoculation into the tip of the tail can be successfully employed, the coldness of the region and the scantiness of the connective tissue preventing any dangerous increase of the bacilli in the cooler season. In the heat of summer, however, this is to be avoided as dangerous. The tail is first washed with soap and water followed by a 3 per cent. solution of phenol. It is then punctured with a fine trochar or needle, (sterilized), within two inches of the tip and in a downward direction and the instrument is moved slightly from side to side so as to form a small sac, and is then withdrawn. The sterilized nozzle of the hypodermic syringe is now inserted in the opening and a few drops of the virus injected into the sac. When the nozzle has been withdrawn the thumb may be placed on the external orifice and the end of the tail manipulated to diffuse the virus in the connective tissue. This is usually followed by an insignificant swelling, and a slight rise of temperature. Should the swelling exceed the size of a duck’s egg or if others appear higher up on the tail, they may be freely scarified and covered with a carbolic acid bandage. Or the tail may be amputated above the highest swelling and the stump treated with antiseptics.

6th. The virus prepared by the Pasteur institutes, that of Arloing, Cornevin and Thomas, is the most extensively employed. Forty grammes of the diseased muscle are dried rapidly at 32° C (90° F.) and triturated in 80 grammes of water. This is divided in 12 equal parts and put on plates in two thermostats, six at 100° C. (212° F.) and six at 85° C. (185° F.) where they are kept for six hours, when it forms a dry, brownish powder. One tenth of a gramme (1½ gr.) of this powder is dissolved in five grammes of distilled or boiled water and will furnish ten doses. The animal to be protected is first injected in the tip of the tail or elsewhere with the virus prepared at 100° C., and ten days later with that prepared at 85° C.

By the use of this method in hundreds of thousands of animals on infected lands the mortality has been reduced to less than one tenth of its former amount. It is attended by the one danger which is not always duly appreciated, that unless its use is restricted to herds on ground that is already infected, it endangers the infection of new districts. The spores are not absolutely sterilized at 85° C. Arloing and Cornevin and later, Nocard and Roux have shown that the addition of lactic acid to the liquid which has been weakened for inoculation, restores it to its former virulence, making it a most deadly agent. Galtier says that the virus weakened by heating to 100° C. for seven hours until it will no longer kill a mature Guinea pig, will still kill a new born Guinea pig and acquire all its original virulence in the act. Also that the injection of large enough doses will not only kill the full grown Guinea pig, but at the same time restore the microbes to their former virulence. While recognizing the great economy of the judicious use of such weakened virus, we cannot but condemn the reckless sale by the Pasteur institutes of their products, to be used on animals on all kinds of lands, the uninfected as well as the infected. A great and valuable prophylactic measure should not be used in such a way as to increase the area of prevalence of the disease which is to be prevented, and also the yearly demands for more of the preventive agent. This may appeal to the business instinct, but this should ever be held subordinate to sanitary considerations. The danger might be avoided by making the state the sole distributor of such prophylactic agents, but in any case their use should be forbidden, and as far as possible prevented, upon dense and wet soils that are not yet contaminated by the bacillus.

7th. Kitt secured immunization by inoculating once only, with dried virus which had been subjected for six hours to steam at 100° C.

8th. In different outbreaks, I have taken the blood from the sick animal, or one that has just died, and heated it for over one hour in a water bath, at 100° C., then broken up the coagulated mass in well boiled water, filtered the liquid and used the filtrate for inoculation in doses of 2 drams, repeated the second day. Great care is taken in keeping the whole mass at 100° C. for the requisite length of time; then in heating the upper part of the vessel, which was above the contents and the water so as to char anything adhering to it; to see that hands, instruments, and all articles used have been thoroughly sterilized; and to dip the hypodermic nozzle in carbolic acid before each injection.

It is not claimed that this method is perfect, since severe, advanced cases may have bacilli and even spores in the blood, and the latter would not be sterilized but only weakened. It has, however, several manifest advantages that may be held to more than counterbalance this danger.

_a._ It almost infallibly secures the toxins of the disease prevailing in the particular herd, thus escaping the danger of using the weakened virus of emphysematous anthrax on some other disease (anthrax, Wildeseuche, Barbone, etc.), which has been mistaken for it, and which may not be prevented by this purchased product.

_b._ During life the blood of emphysematous anthrax is usually free from the microbe, and even where that is present it is liable to be in very small numbers, so that we secure either the pure toxins, or if a few germs are present they are so scanty, that weakened as they are by heat, they are without danger to the animal operated on. I have never had occasion to note evil results.

_c._ There is no danger of the spread of the bacillus to new territory, as we secure the material from a herd in the already infected territory, and use it only on the animals on the same land.

The certainty of results with this method, and the comparative absence of danger of injury to the animal operated on, and of all risk of the extension of the area of infection appeal to me so strongly, that I would not willingly resort to the purchased products, except where it proves impossible to secure the virus on the spot.

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.

SUPPRESSION AND PREVENTION OF ANTHRAX IN HERDS.

Less simple or easy than in plagues. Germ survives in soil and water.
Extinction not always possible. Killing: conditions demanding it: when
unwarranted. Kill without shedding blood, or opening carcass. Body
burned: if buried, 5 feet deep, in porous soil, distant from wells,
ponds, and rivers. Fence graves, burn grass. Disinfection of hides,
litter, fodder, manure, excretions, stalls, etc.: of bodies that must
be moved, of buildings, yards, utensils, etc. Isolation of unaffected
on porous soil; surveillance. Sales interdicted. Milk, butter, cheese.
Immunization: by toxins which stimulate leucocytes to form defensive
products: antitoxins. Eosinophile cells, action of spleen, and liver.
Mellituria. Protection by a minimum dose: by weakened virus—modes of
lessening potency, Pasteur’s “vaccine”, its drawbacks and dangers, its
technique; by soluble toxins in sterile solution, author’s experience,
apparent failures, advantages. Drainage—Æration of land. Prevention of
importation and diffusion. Therapeutic treatment.

Prevention of anthrax in animals is equally important for the sanitation of herds and human beings. It involves the purging from the anthrax bacillus of the infected lands and the drinking supplies, and in this respect the disease is much less amenable to thorough and speedy extinction than is a simple plague in which the germ does not live and multiply outside the animal body. In some localities the extinction of the germ may be confidently counted on and secured; in others, it may be impossible and other measures of protection must be resorted to.

_Killing of the Sick and Disposal of the Carcass._ This is not always so imperative as in the obligatory parasitic infections, since the destruction of the sick, still leaves the germ present in the soil and water. If, however, the infection has just been introduced, on hitherto uninfected soil, by the arrival of new animals, and, if the new location is in any way favorable to permanent colonization by anthrax bacillus, and, if the diseased and suspected animals cannot be kept secluded so as to absolutely exclude these dangers, or again, if the diseased herd or its remnant is to be moved on to another locality, slaughter is the obvious sanitary measure.