LECTURE XXXVII 

 HEMORRHAGIC SEPTICEMIA 



This group of diseases is important because of its many forms, 

 and because medical treatment, so far as we know, is useless, 

 and prevention is very uncertain. Those who have had a 

 chance to study outbreaks have often been unable to trace any 

 connection between one outbreak and another, or to trace a 

 previous history for any given outbreak, except that local out- 

 breaks on farms often follow the advent of stock from public 

 stockyards. This disease is worthy of serious consideration, be- 

 cause it is widespread and fatal. It appears suddenly at any 

 season, and under all sorts of conditions ; a number of animals 

 die, and the disease may disappear as suddenly as it came. 



Etiology. — The specific cause of this disease in cattle is appar- 

 ently Bacillus hovisepticus. This is one of a group of very sim- 

 ilar bacteria, which cause a group of similar diseases in different 

 classes of stock, e.g., chicken cholera, hemorrhagic septicemia of 

 cattle and of sheep, swine plague, septic pneumonia of calves, 

 etc. All are characterized by hemorrhages in the tissues or 

 under the skin, mucous membranes or serous membranes. In- 

 fection may be caused by inoculation or through the respira- 

 tory or alimentary mucous membranes. 



History and development. — The onset is usually sudden and 

 unexpected, but in some outbreaks the onset is rather slow, 

 and the cases are chronic. The period of incubation is prob- 

 ably only a matter of a few days. Season and climatic condi- 

 tions apparently have nothing to do with the prevalence, viru- 

 lence or disappearance of this disease. The death rate is usually 

 high. 



Symptoms. — Symptoms in the living animal are variable and 

 uncertain. There are several fairly distinct types of the dis- 

 ease in sheep and cattle, and symptoms vary accordingly : Some 

 cases are marked by superficial swelling, severe inflammation, 

 and small hemorrhages of the mucous membranes of the eye, 



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