Diseases of the Circulatory Organs 



Section I. 



DISEASES OF THE PERICARDIUM. 

 1. Pericarditis. 



Occurrence. Pericarditis is not a very prevalent disease. 

 It occurs most frequently in cattle in the form of traumatic 

 pericarditis, inflammations of the pericardium from other 

 causes being much more rare, and in all probability usually 

 tuberculous in origin. Still more rarely the disease is observed 

 in horses,. in which it usually occurs as a sequel of croupous 

 pneumonia. It occurs a little more often in dogs, usually on 

 a tuberculous basis, less often in distemper or other diseases. 

 In hogs pericarditis is not very rare, appearing most often in 

 swine plague, less often in erysipelas. In fowls the disease 

 is also observed occasionally, usually as a complication of 

 cholera and chicken plague, less often in tuberculosis. 



Etiology. The occurrence of pericardial inflammation is 

 due, almost without exception, to the immediate influence of 

 infectious substances, although these often become effective 

 only if certain predisposing conditions are also present. 

 Searching bacteriological examinations have not been made 

 very often with respect to pericarditis in animals, but those 

 that have been reported, and also the mode of onset of the 

 disease, permit the assumption that the infectious suTjstances 

 mentioned below are particularly concerned in the production 

 of pericarditis. The Bac. bipolaris may be active in this 

 manner, not only alone but also in association with other 

 bacteria ; in fact, there is hardly one of the diseases for which 

 this bacterium is responsible that is not occasionally associated 

 with pericarditis. Further, the pyogenic bacteria, the tubercle 

 bacillus, the virus of swine erysipelas, chicken plague, con- 

 tagious pleuro-pneumonia of cattle and of variola may also 

 take part in the production of pericarditis. 



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