54 Swiiie Erysipelas. 



are given water in which contaminated meat has been w^ashed. 



The spread of the disease is also frequently brought about 

 by wandering gypsies who carry the carcasses given to them, or 

 which they dig up, from one town to another, at the same time 

 scattering the viscera in the pastures. Furthermore, butchers, 

 hog herders and castrators may spread the infection, particu- 

 larly through utensils and containers in which meat and meat 

 offal have been kept and which have afterwards been used in 

 feeding or watering. 



By the findings of Olt, Jensen, Bauermeister and Pitt it has 

 been proven that true erysipelas bacilli may be present in the 

 intestinal canal, particularly in the secretion of the tonsils as 

 well as in the mucous plugs of the ileo-cecal valve of healthy 

 animals. It is therefore possible that on the one hand the 

 contagion may be spread through healthy hogs, while on the 

 other the disease may break out in healthy herds without a 

 direct introduction of affected animals or products originating 

 from them. Healthy carriers of bacilli may thus become 

 affected, if through weakening influences such as cold, heat, 

 starvation, etc., their normal resistance is reduced, and the 

 bacilli which were present in the intestinal canal may then set 

 up the disease process. 



In examining the intestines of 66 animals Pitt found the true erysipelas 

 bacilli in 26 eases, and 28 times in 50 tonsil examinations. He believes that through 

 their presence the hog becomes gradually immunised which explains why animals 

 strictly guarded from exposure have been found to possess a lower resistance, 

 such animals becoming severely affected if exposed to infection in spite of all pre- 

 cautions. 



In territories once infected, erysipelas usually recurs 

 almost annually, although with varying intensity, provided that 

 in the meantime no measures have been undertaken for its 

 suppression. This fact also proves that the infection may 

 remain virulent in the soil and in stable floors for a considerable 

 length of time. It will multiply in the summer time and infect 

 young hogs which will then reinfect the soil with their excre- 

 ment and carcasses. 



The bacillus of mouse septicemia (Bac. murisepticus) which cor- 

 responds morphologically and in its cultural characteristics with the 

 erysipelas bacilhis, and which has been formerly distinguished from 

 the latter by its very slight virulence for hogs must at the present 

 time be considered identical with the erysipelas bacillus or as an at- 

 tenuated variety of it. These conclusions were reached by Jensen, 

 Lorenz, Loffler and Prettner, who proved that animals immunized 

 against erysipelas are also immune against the virus of mouse septi- 

 cemia and vice versa. As the virulence of the mouse septicemia bacillus 

 may increase under natural conditions, and as it has been repeatedly 

 found in stagnant, polluted water (Koch), in putrefactive meat 

 (Johne), and in blood of cattle (Preisz), it is possible that the mice 

 affected with septicemia contribute to the dissemination of erysipelas. 



Rohrbach has recently (1909) been inclined to consider the bacillus of swine 

 erysipelas and mouse septicemia as two different micro-organisms, and to group 



