826 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



This disease has been reported from many portions of North 

 America, from some sections of South America and many European 

 countries. It is known under a variety of names, as cornstalk disease, 

 buffalo disease, pneumo-enteritis, etc. 



Bad. bomsepticum produces a serious disease and affects a wide 

 variety of domestic and wild animals. The domestic animals most 

 commonly affected are cattle, sheep, and goats, the disease being much 

 more common among cattle than among other classes of stock. 



The period of incubation appears to be short, six to forty-eight 

 hours. The onset of disease is usually sudden, and the case acute. 

 Haemorrhagic septicaemia does not spread from herd to herd but appears 

 in isolated outbreaks usually at wide distances apart. It is a common 

 experience to find a serious outbreak in one herd without any appear- 

 ance of the disease in another herd in an adjoining pasture, with only 

 a barbed wire fence between. Apparently the virus exists locally and, 

 under as yet unknown conditions of increased virulence or lowered 

 resistance, is able to start a local outbreak. Infection is often im- 

 ported with infected cattle from large stockyards. 



Haemorrhages found at autopsy constitute the most specific and char- 

 acteristic clinical evidence of this disease. Its mortality is very high, 

 running from 50 to 90 per cent. 



Haemorrhagic septicaemia of cattle, chicken cholera, and a number of 

 other diseases belonging to this group are very similar in clinical features 

 and the bacteria which cause these diseases are very similar in cultural 

 and microscopic features. Yet all evidence points to the fact that Bact. 

 bomsepticum acts as a specific causal agent for haemorrhagic septicaemia 

 of cattle. 



The method of infection is still uncertain, probably occurs by both 

 inoculation and ingestion. This disease does not appear to spread easily 

 by simple association or ordinary contact and there is no general 

 atmospheric distribution of Bact. bomsepticum. 



Acute and rapidly fatal cases where the autopsy shows only trifling 

 lesions would indicate the formation of active toxins. The character- 

 istic haemorrhages indicate the production of substances actively toxic 

 for the endothelial cells of capillaries. The fact that these haemorrhages 

 vary in different cases from extensive subcutaneous areas to those that 

 are scarcely visible would seem to indicate that this toxin is produced 

 in greatly varying quantities or is of greatly varying toxicity. 



