OF VETERINARY MEDICINE. 57 



BRONCHITIS. 



Definition. — Bronchitis is the inflammation of the mucous 

 membrane Hning the bronchi or bronchioles. It is divided into 

 three classes, acute, subacute and chronic. The acute form afifects 

 the large bronchi mainly,' but in severely acute cases the 

 bronchioles may become involved. The inflammation is catarrhal 

 in nature on account of the free flow of mucous present. Occa- 

 sionally the air vesicles are also involved in the inflammation, 

 and pneumonia is the result. We may have bronchitis and pneu- 

 monia running at the same — broncho-pneumonia. 



Bronchitis is very common in the horse, dog and man. The 

 same phenomena are in all cases. It usually runs the first and 

 second stages of inflammation and then an absorption of the 

 inflammatory products takes place, the case terminating by reso- 

 lution. But it may become chronic, especially in man and cattle. 



Acute. — The inflammation runs from 10 days to 4 weeks 

 and terminates favorably. In an unfavorable case, say one 

 which runs on to the third stage, the mucous follicles suppurate 

 and an absorption of the toxins and poisonous products takes 

 place and 90% of such cases die from septicemia in 2-4 weeks. 

 Another fatal termination of the case occurs in the second stage. 

 In this case the effusion is excessive and occludes the 

 bronchioles. The animal would die quickly from asphyxiation 

 if the condition were extensive enough. But it is usually local- 

 ized and the air in the vesicles of the occluded bronchioles be- 

 comes absorbed and the vesicles collapse, producing atelectasis. 

 the so-called foetal lung. It is small, blue, more or less solid 

 and does not crepitate. 



Etiology. — The cause of bronchitis is usually exposure to cold 

 when the animal is tired. Exhaustion lessens the powers of 

 resistance. Acute bronchitis may develop from laryngitis. It 

 may be prodiiced by impure air, such as we find in close stables, 

 on board ship, etc. Introduction of foreign bodies into the 

 bronchi, medicine, food or any other body, will cause bronchitis. 

 It is more common in children and dogs. Attempt to drench an 

 ox which is in a comatose condition and the failure of the 

 epiglottis to close down may cause asphyxia and at any rate acute 



