CHAPTER XLIX. 



SPOEADIC DISEASES— continued. 



LOCAL DISEASES— con^mwed 



(/) DISEASES OF THE RESPIEATOEY OUGA'SS— continued. 



INFLAMMATION OF THE RESPIEATOEY OEGAXS— 

 BEONCHITIS. 



Division. — This disease may, according to its seat, be arranged 

 under four heads, namely, " tracheo-bronchitis," where the lower 

 part of the trachea and larger tubes are the main seat of the 

 inflammation ; " bronchitis proper," where the medium-sized 

 bronchi are the chief seats of the disease ; " capillary bron- 

 chitis," where the smaller bronchi are chiefly implicated ; and 

 catarrhal, lobular, or broncho-pneumonia, where the smallest 

 bronchi and alveolar walls are involved in the inflammatory 

 process. For simplicity of description I shall retain the generic 

 term bronchitis, dividing it into acute and chronic. 



The character of the inflammation, whatever part of the 

 respiratory tract may be affected, is what is understood as catar- 

 rhal — that is, an inflammation in which, instead of an exudation 

 rich in fibrin, there is a fluid secretion containing a large quantity 

 of mucus and cellular elements. In this particular it differs 

 most essentially from inflammation of the lungs, originating 

 in the parenchyma and from pleuro-pneumonia, in which the 

 pleural surface as well as the lung structure is involved. The 

 exudate in these is termed " croupous " or fibrinous. 



Causes. — Bronchitis, wherever its seat, is generally due to 

 exposure to cold ; it may supervene on an attack of ordinary 

 catarrh, particularly if the animal be neglected, exposed to wet 

 and cold, or kept in ill- ventilated stables. It may also arise with- 

 out any premonitory catarrhal symptoms in both horses and cattle 

 during voyages by sea, particularly if the weather be rough and 

 stormy, and the animals battened down. During 1877 the 

 author had the opportunity of seeing bronchitis assuming the 

 form of suffocative catarrh, and which proved fatal to many, 

 nmongst foreign horses impoitcd at Leith. An instructive fact 



