6 BULLETIN 674, U. S. DEPARTMENT OF AGRICULTURE. 
In sheep, young animals which have just been weaned gre found to 
be most susceptible, the disease manifesting itself in an acute form. 
There is marked depression, high temperature, labored respiration, 
loss of appetite, muscular trembling, and frequently colicky pains. 
A subacute and a chronic form of the disease are also recognized, the 
latter affecting principally older sheep. Aside from the febrile 
changes, weakness, etc., there is noted in the subacute form a dis- 
charge from the eyes and nose which at first is serous, later becoming 
purulent. There may be also pulmonary impairment (pneumonia), 
or there may be evidence of enteritis. Occasionally the symptoms 
‘subside only to return in a more chronic form, which manifests itself 
principally as a chronic affection of the lungs, with gradual emacia- 
tion of the animal. Sometimes the joints are involved, swelling of 
the knee joints being noted in some cases. 
In swine the disease sometimes manifests itself in a peracute form, 
the animal. showing symptoms of a general septicemic condition. 
Red spots may be noted on various parts of the body, especially 
around the ears and on the neck and rump. When affected with 
this form of the disease the animal usually dies within a few hours 
after the first manifestations of symptoms. In acute swine plague 
the disease usually occurs as a necrotic pleuropneumonia. There is 
labored respiration, dry, spasmodic cough, a slimy discharge from 
the nose, sometimes a purulent conjunctivitis, cyanotic membranes, 
constipation followed by diarrhea, the feces sometimes containing 
blood. The animal becomes greatly emaciated and usually dies in 
from 1 to 2 weeks. Sometimes the acute form changes into the 
chronic type, In which case the acute symptoms subside, and the 
cough and evidence of pulmonary involvement continue for a con- 
siderable time. Progressive emaciation occurs and a chronic inflam- 
mation of the joints may develop. The animals die in from 3 to 6 
weeks from complete exhaustion. Sometimes, however, the lung foci 
may become encapsulated, and the animals may even be fattened in 
spite of the condition of the lungs. 
ANATOMICAL CHANGES. 
. 
Swellings will be found in the subcutaneous tissues. If these 
enlargements are examined they are found to consist of collections 
of jellylike material tinged with blood. Occasionally they are lm- 
ited to a single shoulder or flank, when they may be mistaken for 
blackleg. The lymph glands are enlarged and are injected with 
blood. The mucous membranes which line the respiratory tract 
are similarly affected. False membranes composed of fibrinous exu- 
date may develop in the throat. The spleen remains normal. Hem- 
orrhages are constant in the connective tissues around the kidneys 
and within the walls of the intestines. 
9 

_ ae oe 
a ee ee 
