32 DISEASES OF THE LARYNX 



The inflammatory edema may be primary due - to the 

 causes of inflammation, or secondary and associated with 

 purpura, glanders, pyemia or pneumonia. 



The non-inflammatory edema is the result of the venous 

 congestion of the larynx due to chronic heart diseases, 

 traumatic pericarditis of the ox, and compressions of the 

 jugulars in horses from ill-fitting collars. 



Symptoms. — The symptoms in both of these conditions 

 are much the same except that the non-inflammatory form 

 usually develops more slowly. Clinically, edema of the 

 glottis is manifested by a severe inspiratory dyspnea of sud- 

 den development. The patient shows marked "air hunger" 

 by standing with head held extended, anxious expression, 

 general outbreak of sweat, forefeet apart, and rarely saliva 

 and food dropping from the nose and mouth. The dyspnea 

 is attended by a loud roaring sound occurring at each inspira- 

 tion. The mucous membranes become bluish and the pulse 

 and respiration increased. Sometimes paroxysms of cough 

 are present. Unless relieved the patient may die in a few 

 hours. Some cases recover spontaneously, however. 



Prognosis. — The prognosis is not favorable unless treat- 

 ment is administered early. 



Treatment. — The treatment consists in performing trache- 

 otomy, and in cases due to heart diseases, etc., blood-letting 

 ' may be practised. In milder cases Lloyd's lobelia (20 c.c. 

 subcutaneously) has given good results. 



PARALYSIS OF THE RECURRENT NERVE. 



Roaring. 



Definition. — Roaring may be defined as an unsoundness 

 characterized by dyspnea (always inspiratory), and cough 

 due to paralysis of the left recurrent nerve. The condi- 

 tion is always chronic and can be relieved in about 80 per 

 cent, of the cases by operation. 



Etiology. — From a practical standpoint recurrent paralysis 

 may be classified as primary or secondary. 



The causes of the primary paralysis are not understood. 

 It seems as if heredity played" a part in that stallions and 



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