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.