CHAPTER XVII. 



CONTAGIOUS DISEASES— continued. 

 PLEUEO-PNEUMONIA CONTAGIOSA. 



Definition. — A contagious febrile disease, peculiar to horned 

 cattle, supposed to have originated in Central, and has been 

 conveyed to all parts of Continental Europe, to Britain, 

 Africa, America, Australia, India, and New Zealand. It is 

 due to a contagium, which gains access to the system by the 

 lungs, and wliich after an incubative period of from two to 

 three weeks to as many months, induces complications in the 

 form of extensive exudations within the substance of the lungs, 

 and upon the surfaces of the pleura, finally resulting in consoli- 

 dation of some portions of the lungs, occlusion of the tubes, 

 embolism of the vessels, and generally adhesion of the pleural 

 surfaces. In some cases there is extensive and rapid destruction 

 of lung tissue, with death from suffocation ; but most commonly 

 the disease is of a lingering character, symptoms of great pro- 

 stration manifesting themselves, with blood poisoning from 

 absorption of the degraded pulmonary exudates, and death from 

 marasmus and apncea. 



Synonyms. — Lung disease, pleura, new disease, new delight 

 (Yorkshire), pulmonary murrain, epizootic pleuro-pneumonia, 

 &c. ; called by the Germans lungen scuchc and 2^cri-237ieu77i07iia 

 exudativa contagiosa; by the Trench maladie de poitrine du gros 

 hitail and peripnetimonie contagieuse. 



PATHOLOGY AND SYMPTOMS. 



There is much variety in the manifestations of the disease 

 in some instances, more especially during its first outbreak in a 



