PULMONARY EMPHYSEMA. 45 



function, and seeming in no wise impaired by the process 

 passed through. 



PULMONARY EMPHYSEMA. 



Synonyms. — Asthma, broken-wind, heaves, etc. 



Definition. — A dietetic disease of a non-inflammatory 

 character, characterized by difficult and peculiar respiration, 

 and the presence of a prolonged and deep cough, known as 

 the broken-winded cough. 



Pathology. — The pathology of broken- wind is not as yet 

 fully understood, being more or less hidden in obscurity, the 

 theories regarding it being many and speculative. On 

 making post-mortem examinations of broken-wind, it is 

 usual to find vesicular or interlobular emphysema of the 

 lungs. The emphysematous condition, however, is the 

 result, and not the cause of the disease. The trouble, in all 

 probability, originates in the digestive system, from the use 

 of bad food, or other causes; the digestive organs become de- 

 ranged, causing indigestion and irritation of the pneurao- 

 gastric nerves, which send branches to the lungs. The 

 perverted nervous influence, thus reaching the lungs, causes 

 spasmodic contraction of the muscular tissue of the air-cells, 

 followed as a matter of course by a decrease in size of the 

 cell itself. This condition is followed in course of time by 

 dilatation and rupture of the air-cells, constituting pulmonary 

 emphysema. There may be a few cases in which the lesion 

 of the pneumogastric nerve occurs as a result of pneumonia, 

 bronchitis, etc. 



Causes. — Broken-wind, as before stated, may be caused by 

 injudicious feeding, or by a supply of bad food, or bulky or 

 dusty food of any kind, as clover hay, the stomach being 

 kept in a state of distension. Cold may also exert a certain 

 amount of influence in the production of broken-wind — 

 allowing an animal to run out all winter, exposed to cold 



