ROARIXG — COUGH. 75 



may depend on thickening of the mucous lining of the 

 nares (apertures), pharynx, or larynx, or on fibrous growths 

 in these regions ; but the majority of cases are the result 

 of paralysis, wasting, and fatty degeneration of the whole 

 of the intrinsic muscles of the left side of the larynx 

 supplied by the recurrent nerve. The tube through which 

 the air passes being narrowed, the characteristic noise is 

 produced. Most roarers are wheezers, and also grunters, 

 and in the lighter breeds are whistlers. (Dun.) 



Percivall ligatured a horse's windpipe moderately tight. 

 It roared when trotted. He next compressed the pipe to 

 about half its natural calaber. The animal whistled. He 

 then drew the cord with all his strength. A minute af- 

 terward the horse staggered a good deal, fell, struggled 

 violently, and expired in two minutes after falling. The 

 ligatured part of the windpipe admitted a crow's quill. 

 In the two first experiments the sounds were louder in 

 inspiration than expiration. 



Remedy. — ( Spurious roaring/ depending on cold, in- 

 fluenza, or strangles, is sometimes treated successfully by 

 stimulation of the throat, and by potassium iodide and 

 arsenic internally. 



' True roaring/ depending on muscular wasting, is in- 

 curable. Smart blistering, the actual cautery, and gal- 

 vanism in the earlier stages, sometimes retard wasting. 

 Slow, easy work. A pad fitted on the nostrils, regulating 

 the supply of air, lessens the noise. A tube in the wind- 

 pipe affords relief. (See Fig. 5.) Removal of the para- 

 lyzed vocal cord is useless. Removal of the aretenoid car- 

 tilage is seldom permanently effectual. 



For doses, see pages 13 to 29. 



COUGH 



Is symptomatic of various diseases. It may remain after 

 its cause is removed. It sometimes becomes chronic, es- 

 pecially if neglected* 



