DISEASES OF THE EESPIRATORY SYSTEM. 143 



Give the definition. 



This is a chronic inflammation of tlie connective tissue of the 

 lungs, characterized by an increase of this tissue, whicli compresses 

 the tissue proper and interferes with its normal functions. 



What is the pathology ? 



This is more frequently seen in cattle than in the equine race; 

 when seen, it is usually unilateral, the affected side being somewhat 

 sunken. 



If the chest cavity be opened, the heart will be found drawn 

 toward the affected side; the lung not affected becomes emphy- 

 sematous and enlarged. 



Give the aetiology. 



It may follow acute pneumonia, or pleurisy with effusion, which 

 causes compression of the lung. 



It may follow chronic bronchitis, with dilatation or emphysema. 



What are the symptoms ? 



These vary according to the complication. 



After the symptoms of pneumonia, etc., have subsided, dul- 

 ness on percussion remains; there is a loss of the respiratory mur- 

 mur, or, if bronchial dilatation is present, there is cavernous or 

 amphoric respiration. 



The affected side is sunken, and not so movable. 



Cough is present, and there is some interference with the 

 breathing on exertion. 



Indicate the treatment. 



Look after the general health of the animal; give tonics and 

 absorbents, the iodide of potassium being the best. 



Good food, moderate exercise or work, and fresh air. 



PULMONARY EMPHYSEMA. 



Name the synonyms. 



Emphysema, heaves, broken wind, chronic dyspnoea. 



Define pulmonary emphysema. 



This is a chronic, non-febrile, pulmonary disease, with either a 

 dilatation or rupture of the vesicular structure of the lungs, and 

 characterized by a tlry ahorlive cough and a double expiratory act. 



