Definition. Historic notes. Geographical distribution. Animals
susceptible: Young cattle after weaning, sheep, goats; horses, asses
and white rats, have local swelling; dog, cat, pig, bird and man
immune. Immune animals succumb if injected with lactic acid, or
proteus vulgaris, or violently exerted (sarco-lactic acid). Causes.
Bacillus anthracis emphysematosa, 3 to 10μ by 5μ, stains violet with
iodine, anærobic, sporulates in living body, hence seen as rod, club,
and round, spore. Lives in exudate, not in blood nor on surface. Table
comparing with anthrax bacillus. Vitality: resists drying, cold, 98°
F., weakened by 139°, sterilized by 212° F. for 20 minutes, by strong
antiseptics. Lives in dense clay, hard pan, and waterlogged soils
holding little oxygen. Accessory causes: lactic and other organic
acids, overwork, potash salts, alcohol, salt, proteus vulgaris,
micrococcus prodigiosa, low condition, debility, plethora, chills,
change to warmth, youth, melting snows, freshets, drying of wet lands.
Symptoms: incubation a few hours, disease 12 to 70 hours.
Hyperthermia, swelling in loose connective tissue, shoulder, quarter,
arm, thigh, neck, trunk, palate, base of tongue, pharynx, tender
point, rapidly enlarges, spreads, crepitates, percussion resonance,
finally cold, insensible, and withered. On incision black, bloody
pulp, or frothy. Peripheral gelatinoid exudate. Subsidiary lymph
glands enlarged. Cases with deep seated exudate. Diagnosis: from
malignant œdema and anthrax. Lesions: early decomposition, bloating,
in swelling blood extravasation with gas bubbles and lymph exudate,
muscle beneath dirty brown or black, breaking down when pressed, shows
waxy or fatty degeneration, and many leucocytes and cell forms. Lymph
glands and plexuses blood gorged. Extravasation may be in internal
organs. Liver congested. Spleen rarely enlarged. Treatment: Chloride
of iron internally, ammonia iodide and ol. terebinth externally.
Scarify and use hydrogen peroxide or potassium permanganate.
Antitoxins. Prevention: drain and till soil, apply quicklime to muck,
exclude new animals just from infected districts, disinfect buildings,
close infected wells and streams, seclude the sick, burn, cook or
dissolve carcasses, or fence graves. Bleeding purgation, diuresis,
uniform good feeding, setoning. Immunization by heated and sterilized
culture; by toxins passed through a porcelain filter; by minimum dose
intravenously; by injection into trachea; by inoculation on tip of
tail; by inoculation with Pasteur weakened virus; by heat sterilized
virus.
_Synonyms._ Symptomatic Anthrax; Black Quarter; Quarter Ill; Black Leg;
Rauschbrand; Charbon Symptomatique.
_Definition._ An acute infectious bacteridian disease manifested by
hyperthermia, lameness, and a localized, hot, painful swelling on the
shoulder, quarter, leg, neck, trunk or elsewhere, tending to emphysema,
and gangrene and when incised showing black extravasated blood, clotted
or frothy.
This affection was long confounded with anthrax proper, but was
differentiated by the observation of Wallraff (1856), Boulit-Josse,
Vernant, Pfisterer, Feser, and others and finally Bollinger in 1875
found the motile bacillus. Arloing, Cornevin and Thomas (1879–84)
thoroughly substantiated this position, and devised a method of
immunizing by inoculation. Feser had however seen the motile sinuous
rods in the exudate as early as 1860, and even produced the disease by
the inoculation with mud from infected Alpine pastures.
_Geographical distribution._ Emphysematous anthrax prevails in limited
areas, and particular buildings in Europe, Asia, Africa, Australia and
America, and in all climates from the tropics up to the sub-Arctic. It
is however most prevalent in spring, summer and autumn. It is not
uncommon at the breaking up of the winter snows. It is especially
prevalent on damp, undrained land or on such as has dried up in the
heats of summer, and has become less prevalent in many localities in
connection with drainage and careful cultivation.
_Animals susceptible._ The disease is especially common in young cattle,
from three months to four years of age. Calves fed on milk are rarely
attacked, being in a sense carnivorous and sometimes immunized by toxins
from the dam. Cattle over four years usually escape, having already
become immune if kept in an infected locality. If brought from a
noninfected place they are, at any age, as susceptible as the young.
Sheep and goats contract the disease only exceptionally, but like the
Guinea pig are easily infected by inoculation. Horses, asses and white
rats have only a circumscribed swelling in the seat of inoculation, and
foals and buffalo calves sometimes contract it casually. Carnivora and
omnivora, (dog, cat, pig, bird, man), and the rabbit are virtually
immune.
Immune animals may, however, be made to succumb under special treatment.
In a rabbit inoculated at the same time with the microbe of black
quarter and proteus vulgaris, or micrococcus prodigiosus, or if injected
with a little lactic acid, the disease develops promptly and fatally.
Over-exertion, producing sarco-lactic acid will also lay the system open
to attack. The reduction of the vitality and resistance of the muscle of
the rabbit by a contusion, bruise or lacerated wound, or by injecting it
with acetic acid, potash salts, alcohol, or common salt, will render the
inoculation pathogenic. Again, the introduction of the black quarter
microbe into the aqueous humor of the rabbit, where there are so few
defensive leucocytes, entails an active proliferation and a fatal
result.
_Causes._ The essential cause of emphysematous anthrax is a rod-shaped
germ, variously known as =bacillus anthracis emphysematosa=, =bacillus
Chauvæi=, =Rauschbrand bacillus=. This is a rod-shaped microbe, with
rounded ends, found singly or connected in pairs, or very short
filaments. The bacilli are 3 to 10µ long, by .5µ broad, or when
sporulating, 1.1 to 1.3µ. They form spores even in the body of the
affected animal, often assuming a club shape by reason of the spore
formation near one end. If the spore develops in the center they appear
fusiform. They take aniline colors readily, and iodine slightly,
assuming in the last case a violet tint. The staining is unaffected by
heating in melted balsam. The bacillus grows readily in ordinary culture
media, (peptonized gelatine, bouillon, milk, etc.), but, being anærobic,
only under the surface in stick cultures, or under a neutral gas or
vacuum. It grows most rapidly at a temperature of 36° to 37° C. but also
as low as 15° C. The bouillon at 37° C. becomes milky and opaque in 24
hours, and later it clears up, the microbes being precipitated as a free
white powder. In gelatine cultures liquefaction takes place in three
days, and in twenty days the whole mass may be dissolved and the
microbes precipitated to the bottom. Spores may form in the living body
and as these are set free by the granular degeneration of the bacilli,
the virulent exudate and cultures usually show the microbe in three
different forms: 1st; the straight, motile bacillus of one thickness
throughout its whole length; 2d; club-shaped or fusiform bacilli, the
thickening of the end or median part being due to the endogenous
formation of a refrangent spore or spores; and 3d; the free refrangent
spores which have been set free by the degeneration and destruction of
the sporulating bacilli. The microbe is not found on the surface of the
living animal, nor in the blood, for in both the supply of oxygen is too
abundant; it forms its colony under the skin, in the tissues, and above
all, in the mass of extravasated blood or gelatinoid exudate which its
irritation has produced and where air is lacking.
The most marked differential features of the microbes of anthrax and
emphysematous anthrax are contrasted in the following table:—
=Bacillus Anthracis.= =Bacillus of Emphysematous
Anthrax.=