78 Hemorrliagie Septicemia 



Kitt (1883) of Bollinger s Wildsenche, and Loffler (1886) of swine 

 plague, proved that these diseases are caused by small bacilli, all of 

 which showed the same characteristics by taking the stain intensely at 

 the poles and only very slightly or not at all in the middle, therefore 

 resembling somewhat the figure 8. 



Based on a comparative study of these four diseases, Hueppe (1886) 

 came to the conclusion that their causative agents coincided in all their 

 principal morphological and biological characteristics, and that the 

 diseases greatly simulated each other in their course and anatomical 

 changes. From these he concluded that the causative agents of the 

 diseases mentioned represent one species of bacteria, and that the existing 

 differences, especially with reference to their virulence, justified his 

 conclusion that they were varieties of the same species. Inasmuch as 

 in the acute cases there are manifestations of a general blood infection 

 and the presence of hemorrhages in the internal organs, Hueppe included 

 the four diseases in one group and recommended the name of hemor- 

 rhagic septicemia for their designation. 



The observations nmde since these investigations proved the cor- 

 rectness of this conclusion, and have at the same time shown that similar 

 bacteria play an important part in the etiology of other diseases. Thus, 

 this was established by Poels (1886) for the infections pleuro-pneumonia 

 of calves, by Oreste and Armanni (1887) for the barbone disease of 

 buffalo, b}^ Galtier (1889) for the infectious pneumo-enteritis in sheep. 

 Therefore these diseases may also be included in the group mentioned. 



In the diseases mentioned and also others of less importance the 

 bipolar bacteria appear to be the exclusive factors in the development 

 of the pathological processes. Lignieres (1900), however, includes those 

 diseases in which the bipolar bacilli are usually involved only indirectly, 

 by predisposing the body for an infection with other bacteria. Such 

 diseases are influenza or pleuro-pneumonia of horses, and distemper of 

 dogs and cats, to which Xocard, on the strength of his own investiga- 

 tions, added white scours and the catarrhal pneumonia of calves which 

 are due to navel infections. In the meantime Lignieres in supporting 

 Trevisan's suggestion, named the bacteria of chicken cholera and of the 

 related diseases, pasteurella, and the diseases caused by these bacteria 

 pasteurellosis. This nomenclature has been accepted in general by the 

 French authors. 



Recent experiences with the diseases mentioned and a more accurate 

 consideration of the etiological part of the ovoid bacteria, make the cor- 

 rectness of Lignieres' conception very doubtful, and at least they appear 

 to be remote. While it cannot be doulited that the bacteria under dis- 

 cussion may independently produce diseases, their occurrence in affected 

 organs and tissue fluids is not a sufficient proof that the disease was 

 originally produced by them. Since they may not infrequently be met 

 in healthy animals, it is possible for them to invade secondarily the 

 tissues which have been already affected from other causes. It will 

 reciuire further investigations to establish the significance of their pres- 

 ence. However, their part in distemper of dogs, in pneumonia of calves 

 and pigs, in the pectoral form of hog cholera, and in influenza, may even 

 now be accepted as secondary. On these grounds it appears advisable 

 to restrict the conception of Lignieres' pasteurellosis, and therefore 

 only those diseases will be considered here in which it has been positively 

 established that the ovoid bacteria play the primary etiological part. 

 The results of investigations in the future will show whether a change 

 of this viewpoint will be necessary. 



