20 DISEASES OF SWINE AND OTHER ANIMALS. 



November 1, 54 visits to 2G cliflereiit herds of diseased swiue, and 53 

 l^OHt-mortcm examinations, and liave examined microscopically the blood, 

 diverse other lluids, morbid products, and tissues of 42 sick or dead ani- 

 mals. 



For the purpose of ascertaining the cause or causes of the disease, I 

 have also made numerous experunents, 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 

 Avhich may, more appropriately, be called swine-plague— a name which 

 I shall use exclusively hereafter — is a disease siii generis, peculiar to 

 swine, is neither cholera nor anthrax ; it somewhat resembjes the enteric 

 fever, or dothinenteria, of man, but is not identical with the same ; is 

 communicated from one animal to another by direct and indii'ect 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 tlie 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. Tlie causes of these differences will 

 hereafter be fnlly explained. 



To convey a better idea of the features of swine-plague, as presented 

 in the liA'ing animal, I shall first give an outline of all the sjTuptoms ob- 

 served in a large number of hogs and pigs, and shall append, in order 

 to sliow wliat 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 l(!ss cougliing. The symptoms of shivering and sneezing are gen- 

 erally noticed. At the beginning of the disease the temperature of the 

 body seems to be increased. The thermometer indicated from 104° to 

 10(io V. Still, not nuich reliance can be placed on the temperature, as 

 indicated by the thermometer. In some cases it Avas found to be very 

 high — in one case as high as 111° F. — and in otliers below normal. It 

 was ahviiys more or less variable, and has been found decreasing at the 

 xvvy liciglit of the disease. I liave come to the conclusion that in dis- 

 tiases of swine llicrmometry is of a very doubtful practical value, be- 



