DISEASES OF THE BRONCHI. 147 



time, the collapsed lung-tissue becomes atrophied, and re- 

 placed by fibrous material, and compensatory vesicular 

 emphysema of the neighbouring lung-tissue is developed. 



Pulmonary collapse is more geuerally met with in cases 

 of secondary bronchitis and where the animal is in a very 

 debilitated condition. 



In all cases of bronchitis the bronchial glands are en- 

 larged, and become more or less friable, and in the later 

 stages still larger, owing to the accumulation of inflamma- 

 tory products. 



At an early stage in acute bronchitis the epithelium of the 

 tubes is shed, and is not reproduced until after subsidence of 

 inflammation, and the mucous membrane is thus left in an 

 exposed condition. This shedding of the epithelium is 

 probably due to infiltration of the basement membrane of 

 the tubes. Bronchitis may end fatally by absorption of 

 putrescent catarrhal products, by gangrene of the collapsed 

 lung, or by sudden and copious effusion into the bronchi. 



Treatment of Bronchitis. — The horse should be warmly 

 clad, and placed in a well-ventilated loose box, and the 

 diet should be liberal, nutritious and laxative. 



It very rarely happens that we see a case of bronchitis in 

 its earliest stage, in which anodynes, as, for instance, 

 opium in moderate doses, are likely to be efiicacious in 

 reducing the irritation. After the early stage is passed, it 

 is our object to promote the natural course of the inflamma- 

 tion, as we can no longer expect to cut short the attack. 

 With this object in view the animal should be made to inhale 

 hot- water vapour, which may be medicated with camphor 

 or carbolic acid. In all cases of acute bronchitis, inhalation 

 is of the greatest importance, but especially when the dis 

 charge is very profuse, is it of special efficacy in promoting 

 the discharge from the bronchial tubes. If there be any 

 laryngeal inflammation, stimulating embrocations, as, for 



10—2 



