HOG CHOLERA. 
440 
In chronic cases the same symptoms were in evidence, al¬ 
though less pronounced and the course of the disease more pro¬ 
longed with progressive weakness and emaciation supervening. 
Post-mortem lesions were chiefly in evidence affecting the lym¬ 
phatic glands, lungs, heart, kidneys, spleen and intestines. The 
lymphatic glands were usually observed to be markedly reddened 
and enlarged; the lungs showed many small ecchymosis and 
large pneumonic areas, dark red in color, consolidated and sharply 
defined from the healthy lung. Ecchymosis was also observed on 
the heart surface. The kidneys were darker in color than normal 
and presented numerous petechia (the turkey egg appearance). 
The spleen in many cases was greatly enlarged, although in a 
few cases it also appeared smaller than normal. The intestines 
in acute cases, where the duration of the disease had been short, 
petechia and ecchymosis were noticed on the outer surface and on 
the inner surface areas of the mucosae often appeared congested, 
inflamed and more or less swollen. 
In chronic cases somewhat similar lesions were observed as 
those in acute cases, together with characteristic ulcerations of 
the intestines, noticeably round the region of the ileo-ceacal valve, 
as well also as thickening of the mucosae in other parts of the in¬ 
testines. 
While formerly the specific cause of hog cholera was thought 
to be due to the bacillus suis, it has in recent years been demon¬ 
strated by Dorset and others that this germ only plays the part 
of an associated or secondary invader and the true infective agent 
has not been demonstrated, but is due to a filterable virus which 
is ultramicroscopic, so that at present there is no means of de¬ 
termining the diagnosis of hog cholera, other than by the char¬ 
acteristic symptoms and post-mortem lesions and its infectiveness 
or contagiousness to other hogs which can be proved by the trans¬ 
mission of the blood from infected to healthy animals as well also 
as by the placing of diseased animals in contact with healthy pigs 
which sooner orrr^P contract and develop the disease. 
Meeting place A. V. M. A., Das Deutsche Haus, Indianapolis, 
August 26 to 30. 
