38 DISEASES OF THE BRONCHI 



ditions will be associated with those of bronchitis. In 

 practice chronic bronchitis is most commonly met with in 

 horses suffering from "heaves" (pulmonary emphysema). 

 It also occurs frequently in dairy cows in the Eastern States, 

 especially during raw, damp weather. The principal symp- 

 toms are a persistent cough and slight nasal discharge which 

 is usually wiped off with the tongue. There are no consti- 

 tutional symptoms. The course is benign except in neglected 

 cases. 



Course.-^The acute form usually terminates in two to three 

 weeks in healing. When the smaller bronchi become 

 involved (bronchiolitis) the course is more prolonged and is 

 apt to lead to bronchopneumonia and death. Death may 

 also result from pulmonary edema. 



Chronic bronchitis may last for months or years depend- 

 ing upon the cause. Generally in time the patient becomes 

 anemic, cachectic, and finally death results from inanition. 



Diagnosis. — ^The diagnosis of bronchial catarrh is, as a rule, 

 not difficult. The presence of the characteristic rales or 

 rhonchi are evidence enough especially when taken into 

 consideration with the other symptoms and course of the 

 disease. It is sometimes impossible to determine whether 

 the bronchitis is primary or secondary. Generally, however, 

 when bronchitis is secondary to some acute infectious disease 

 the high temperature which the patient shows is indicative. 

 When associated with a chronic infection a thorough clinical 

 examination of the patient will usually reveal the presence 

 of a primary disease (tuberculosis, tuberculin test; glanders, 

 various tests) . 



Prognosis. — A primary catarrh of the larger bronchi is 

 usually more benign than that of the bronchioli. In very 

 young or very old animals on account of the prevalence of 

 bronchiolitis the prognosis is not as good as in animals in 

 the prime of life. Bronchitis, the result of inhalation of 

 smoke or fire, is usually diffuse and dangerous. If pneu- 

 monia develops, which is not common, obviously the prog- 

 nosis is not so good. 



Bronchites which are secondary are governed, from a 

 prognostic standpoint, by the course of the primary disease. 



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