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.
The animal should be killed on the premises to avoid the danger of scattering the infectious discharges in transit; it must not be bled, nor cut open, as the admission of air determines the formation of the resistant spore; and the carcass must be burned, boiled, or rendered in superheated steam under pressure, or finally dissolved in strong mineral acids. If buried, it must be in open, porous soil, well apart from any well, pond, river, or bank where the liquids may leach out, and the body must be wholly covered to a depth of at least five feet. The graves must be well fenced in from all stock, for a number of years, and no forage grown on them can be safely fed to animals, as the bacillus can be brought to the surface by earth worms. I have known cattle to become infected through licking the fluid which escaped above a stratum of clay, on the deep bank of a river, at some little distance from where an anthrax carcass was buried in the surface sandy loam. A covering of coal tar, chloride of lime or of sand charged with sulphuric acid is an admirable precaution.
As a measure of economy the skins may be removed, if at once, on the spot, plunged for 12 hours in a 5 per cent. solution of carbolic acid, or cresyl, or creolin, or in a two per cent. solution of sulphuric acid, and, if the knives and other implements used are placed in boiling water for half an hour. The same will apply to fleeces.