ACUTE CATARRHAL BRONX'HITIS. 473 



CHAPTER XIX. 



DISEASES OF THE BRONCHI. 



I. Acute Catarrhal Bronchitis. 



Definition. — Inflammation of the air-tubes, large or small, 

 leading to the pulmonary air-sacs, characterized by a short, 

 troublesome, rather harsh cough, a soft, frequent pulse, and 

 accelerated breathing. Febrile symptoms often, but not in- 

 variably, precede and accompany the earlier stages. 



Pathology, a. Nature and Causation. — At one time, in 

 veterinary medicine in particular, bronchial inflammation was, 

 as a rule, mixed up and confounded with the same action 

 occurring in the pulmonary tissue ; now we are inclined to pass 

 to the other extreme, of endeavouring to draw a sharp line 

 between this and the other closely related morbid actions 

 taking place in pulmonary structure. In this we are as likely 

 to fall into error as in the former case. 



No doubt there must always exist between inflammation as 

 appearing in the pleural sac, and the same action occurring in 

 the bronchial tubes and vesicular structure of the lungs, the 

 difference in the course and results of this process as exhibited 

 in a serous and in a mucous membrane. 



The disease, while consisting essentially in congestion and 

 inflammation of the bronchial tissues, with an exudation over 

 the bronchial mucous membrane into the tubes, in all cases so 

 far of a similar nature, is yet in many instances modified by 

 the conditions as to general health of the animal attacked, 

 the causes which determme the attack, and the extent of the 

 structures mvolved. 



Of the causes which tend to the production of acute bron- 

 chitis we may be able to recognise two varieties — (a) Those 

 which are of a predisposing character, as constitutional or 

 acquired weakness ; previous attacks of bronchial inflamma- 

 tion ; cardiac diseases of some time standing ; location in 

 certain situations where special atmospheric changes are liable 

 to occur, as prevailing cold winds at particular seasons combined 

 with moisture, (b) Such as are directly exciting, comprising 

 all those connected with exhaustion and sudden exposure to 



