332 REPORT OF THE COMMISSIONER OF AGRICULTURE. 
basis of successful prevention and rational treatment. This plan I have 
executed as far as circumstances and the time granted have permitted 
me to do. 
In order to become thoroughly acquainted with the nature of the so- 
called “hog-cholera,” or more appropriately ‘“swine-plague,” called 
also typhoid, pig-typhoid, enteric fever, pneumo-enteric fever, hog or 
swine disease, &c., | have made during the time from August 2nd. to 
November 1, 54 visits to 26 different herds of diseased swine, and 53 
post-mortem examinations, and have examined microscopically the blood, 
diverse other fluids, morbid products, and tissues of 42 sick or dead ani- 
mals. , 
Hor the purpose of ascertaining the cause or causes of the disease, I 
have also made numerous experiments, a detailed account of most of 
which will be found in this report. After having inquired into the 
causes, I have made other experiments in regard to prevention and 
treatment. 
The following may be considered as the result of my investigations: 
1. DESCRIPTION OF SWINE-PLAGUE. 
The disease, commonly known as “hog-cholera” to the farmers, but 
which may, more appropriately, be called swine-plague—a name which 
J shall use exclusively hereatter—is a disease sui generis, peculiar to 
Swine, is neither cholera nor anthrax; it somewhat resembles the enteric 
fever, or dothinenteria, of man, but is not identical with the same; is 
communicated from one animal to another by direct and indirect infec- 
tion; has usually a subacute course; is extremely fatal, especially 
among young animals; and exempts neither sex, age, nor breed, but 
Seems to prefer, in its attacks, for reasons hereafter to be explained, 
large herds, and is always most fatal in such sties, pens, and yards in 
which many animals are crowded together. Some individual animals 
seem to have more predisposition to the disease than others. The 
morbid process, although in all cases essentially the same, is not re- 
stricted to a single part or organ, or to a set of organs, but can have 
its seat almost everywhere—in the tissue of the lungs, in the pleura 
and pericardium, in the heart, in the lymphatic system, in the peritoneum, 
in all mucous membranes, especially in those of the intestines, in the 
liver, in the spleen, and even in the skin. Only the pulmonal tissue and 
the lymphatic glands are invariably affected. 
2. THE SYMPTOMS. 
The symptoms, although presenting certain characteristics, observed 
more or less in the affected animals, vary considerably in different cases, 
even in one and the same herd, but still more so in different herds, and 
in different seasons and localities. The causes of these differences will 
hereafter be fully explained. 
To convey a better idea of the features of swine-plague, as presented 
in the living animal, I shall first give an outline of all the symptoms ob- 
served in a large number ot hogs and pigs, and shall append, in order 
to show what combinations may occur in an individual animal, a de- 
scription of the symptoms presented by some of my experimental pigs. 
Swine-plague announces its presence very often by a cold shivering, 
lasting from a few minutes to several hours, frequent sneezing, and more 
or less coughing. The symptoms of shivering and sneezing are gen- 
