Historic note. Microbiology: ovoid bacterium, motile, with polar
stain, non-liquefying, chains, grows freely on culture media.
Pathogenic to sheep, goats, dogs, hens, rodents, calf, ass. Views of
Lignieres, Lienaux, and Conte. Symptoms: Acute form in young;
hyperthermia, rapid pulse, troubled breathing, dulness, prostration,
sopor, anorexia, congested petechiated mucosæ, offensive diarrhœa,
emaciation, wheezing, cough, râles, crepitus, percussion flatness,
abortion. Death in 6 hours to 3 days. Subacute form in mature:
symptoms moderate, recoveries the rule. Lesions: fœtid carcass, blood
staining of skin and organs, exudates, petechiæ, swollen congested
lymph glands, peritoneal exudate, congested liver and spleen,
gastro-enteritis, pleural effusion, lobular and peribronchial
exudates, caseation, congested womb, placenta and brain, bacterium in
lesions. Prevention: isolation, disinfection, secretions, manure,
drainage, exclude tame and wild animals. Disinfectants.
Among the different forms of hæmorrhagic septicæmia in sheep, that
observed by Galtier in 1889 in Basses Alpes, and later elsewhere in
southern and western France and in Algiers, must be specially noted. It
seems to be the same affection studied later by Lienaux, Conte, Besnoit
and Cuillé and which prevailed from Tarn in the south of France, to
Vendée in the west, and Somme in the north.
_Microbiology._ The pathogenic factor found in the lesions was an ovoid
bacterium, a little larger than that of fowl cholera, motile,
non-liquefying, with polar staining, and often showing in short chains
of two or three joined end to end. It grows easily and abundantly in all
common culture media, even on potato which fails to propagate the
cocco-bacillus of Lignieres. This, with its ready transmission from
swine to sheep and _vice versa_, apparently serves to differentiate it
from the cocco-bacillus, and the disease from the hæmorrhagic septicæmia
of Lignieres.
_Pathogenesis._ In Galtier’s first observations in Basses Alpes four
separate flocks were infected by pigs brought all from one market, and
placed in or by the pens of the sheep where they sickened and one in
seven died in a few days. Then the mortality began among the sheep and
ranged as follows: 1st flock lost 10 in 37: 2d flock 16 in 25: 3d flock
8 in 20: 4th flock 12 in 22. On one farm 10 sheep were sent to a
neighbor’s just before the arrival of the sick pigs and escaped, and on
another a second flock kept in outlying pens well apart from the home
flock kept perfectly sound.
With cultures of the microbe in vitro, he successfully inoculated sheep,
goats, dogs, chickens, Guinea pigs, rabbits, and, finally, a calf and an
ass. The cultures were inoculated in different cases; intravenously,
into the trachea, pleura, lung, and subcutaneous connective tissue, and
one goat was infected by ingestion.
Lignieres claims that Galtier must have worked with a complex infection
in which his (Lignieres’) cocco-bacillus was an essential constituent.
The evidence of this is, however, lacking, and we must recognize that
Galtier made cultures which showed the close relationship of his
organisms to swine plague, and their lack of complete identity with
those of the Lombriz.
Lienaux and Conte had pathogenic results in a limited number of animals
only (rabbit, mouse, Guinea pig) illustrating the familiar truth of the
variability in the pathogenesis of different specimens of septicæmic
bacteria of the colon group.
_Symptoms._ 1. _Acute Form._ There is a sudden marked rise of
temperature, often to 107° F., with acceleration of pulse and
respiration. Sometimes death follows so early as to prevent the
observation of other symptoms. If otherwise there supervene marked
dulness, prostration, somnolence, anorexia, suspension of rumination,
and more or less tympany of the rumen. The patient is found lying down,
apart from the flock, indisposed to rise, with deep red, congested,
arborescent conjunctiva and other mucous membranes, and petechial spots
on these and on the white portions of the skin. The fæces, at first
moderately firm and moulded in pellets, marked here and there with lines
of mucus, or even blood, become on the second or third day soft,
pultaceous, or watery and highly offensive. Parallel with this,
emaciation advances with rapid strides. Breathing becomes more hurried,
wheezing or snuffling, with a muco-serous, often bloody discharge from
the nose, and an infrequent cough. Careful auscultation and percussion
will often reveal the blowing or mucous râles, the crepitation or
flatness on percussion of broncho-pneumonia. As the disease advances the
petechiæ on skin and mucosæ extend, and extensive deep violet areas show
especially on the inner sides of the arms and thighs, on the under
surface of the tail, on the perineum and under the belly. Abortion is a
common result, the lambs coming dead.
Death may occur in six hours, more commonly in two or three days, or
even longer, the temperature going down to below normal in the last
stages. In case of recovery, convalescence is slow, the animal remaining
emaciated and weak, with lung lesions and persistent cough for a length
of time. These poor imperfectly recovered animals continue to harbor the
microbe and transmit it. Lesions of the liver and other organs, the
result of this disease, are found in sheep that have survived the
affection and are afterward killed for mutton.
_Symptoms: 2. Subacute and Chronic Form._ This is seen in mature sheep
of two or three years, that have been infected when in the full vigor of
life and health, during an open air life and by a limited dose of the
virus. The temperature is less elevated, the circulatory and respiratory
functions less disturbed, the dulness and prostration only moderate, the
interruption of feeding and rumination transient and tympany slight.
Cough and nasal discharge are however present and rather persistent,
diarrhœa may be manifested, and marked emaciation occurs. There may be
congestion of the mucosæ, but petechiæ and extensive bloody
discoloration of the mucous membranes or skin are rarely seen. Abortion
is not uncommon.
Recoveries are the rule in this type of the disease, though in some
cases it will be delayed for weeks and may even then be imperfect.
_Lesions._ In the acute types of the disease decomposition advances
rapidly after death, and the carcass from the first exhales a peculiarly
heavy odor. The skin is discolored, the nasal mucosa is the seat of a
muco-purulent or sanguinolent discharge, the anus is soiled with liquid
fæces, the subcutaneous connective tissue marked by red arborescence and
blood-stained areas, or by a gelatinoid exudation, the muscles at times
deeply colored and petechiated, the lymph glands, especially the
bronchial and mesenteric, are enlarged and congested of a deep red—the
color being highest in the cortical zone. In some old standing cases
these may have softened and acquired a grayish hue. They are rich in the
specific bacterium.
The peritoneum is congested, petechiated, thickened, and more or less
covered with thin false membranes, and it contains from a pint to three
quarts of a sero-sanguinolent liquid which coagulates loosely on
exposure. The liver is congested, with points of blood extravasation,
and zones of degeneration (fibroid, fatty or necrotic), and sometimes
abscess. The congestion extends to the spleen and pancreas. The abomasum
and intestines are the seat of mucous gastro-enteritis. The mucous folds
of the pyloric sac of the stomach are congested, reddened and
petechiated, the small intestine has tracts and patches of congestion,
thickening and softening, Peyers’ patches and the solitary glands are
enlarged, and ulcers may be present on large or small intestines.
Effusion is usually found in the pleura, clear, grayish or bloody, with
flocculi and false membranes, and further branching redness of the
serosa. The mediastinum may be thickened by exudate especially around
the glands, œsophagus and blood vessels. The lung shows lobular,
interlobular and peribronchial exudates approaching at times to the
appearances shown in lung plague, along with the atelectasis, emphysema
and, in prolonged cases, caseation.
Less constant are congestions and petechiæ of the pericardium, heart,
kidneys, vesical mucosa, testicles, ovaries or womb. The blood is dark
and forms a loose coagulum. In case of abortion the umbilical cord is
infiltrated and the placental membranes ecchymotic. The brain and spinal
cord and their membranes are sometimes congested and infiltrated and a
serous effusion exists in the arachnoid.
The bacterium is found more or less abundantly in each of the morbid
lesions.
_Prevention._ Absolute seclusion of the sick and of all their products
is the prime essential. The general distribution of the lesions
throughout the body and the uniform presence of the bacterium in the
lesions indicate that no part of the body and no secretion can be
considered as free from infection. All parts of the body, all
expectoration, saliva, fæces, urine, milk even must be withheld from all
other animals, at least until they have been thoroughly cooked or
disinfected. Manure must be burned, or buried deeply in quicklime.
Contaminated pens, yards, wallows, streams and fields must be abandoned
or thoroughly disinfected.
Galtier found that the virus remained active for six days in putrefying
organic matter at 39° to 75° F.; in 25 days in water, at room
temperature; the refuse litter, fodder, manure, and drainage matter from
the infected place must be carefully guarded against. The virus steadily
loses in force in such media, but remains infecting to animals injected
with it. The most active disinfectants may be used on the pens and yards
(copperas 5%, sulphuric acid 2% solution, or mercuric chloride .2%)
while the contaminated fields should be abandoned for the season. All
droppings may be treated with sulphuric acid (2%), creolin, lysol,
phenic acid or copper sulphate. The susceptibility of practically all
the animals of the farm, demands the exclusion of these, while that of
rodents, renders necessary the further exclusion of wild mammals; and we
may add birds, wild and tame, and if possible flies. The plowing of the
contaminated soil will do much to obviate danger, yet the sheep folds
and pastures should be separated by a considerable distance from any
place where infected animals and objects have been. If drinking troughs
for sound animals have been used by the sick or suspected they should be
emptied and washed with a disinfectant (sulphuric acid 2:100).