624 ROAPJXG DYSPNCEA. 



Hering says that, without doubt, the deformity was conge- 

 nital, and the occurrence of such a case should put practi- 

 tioners on their guard in future, so as to resort to the puncture 

 of the occluding membrane, and cure the roaring. 



IV. Tumours in connection with the pharynx are not un- 

 frequently the causes of roaring. Simple pharyngeal polypi 

 may partially obstruct the larynx, and sometimes may move 

 in position, and choke the animal. Fibrous and fibro-cystic 

 tumours, growing from the epiglottis, or from the arytenoid 

 cartilages, have been met with on dissection in animals known 

 during life to have been bad roarers. 



I have seen bad cases of roaring from melanotic disease in 

 the group of lymphatic glands situated behind the pharynx 

 and below the atlas; also, from similar disease in the lym- 

 phatic glands on the inner side of the parotids. Distension 

 of the guttural pouches by thickened pus will have the same 

 effect. 



V. When the larynx and pharynx are inflamed, roaring is 

 a symptom. We cannot satisfactorily examine horses when 

 affected with sore throat, and must wait for the acute disorder 

 to have passed off. A permanent thickening of the mucous 

 membrane may result, and in some rare cases false mem- 

 branes are thrown out, become organised, and may form 

 septa in the passage, so as to interfere permanently with the 

 respiration. Cline, the celebrated London surgeon, who lived 

 in the first quarter of the present century, said that the dis- 

 order in a horse which constituted a roarer, was caused by a 

 membranous projection in a part of the windpipe, and was a 

 consequence of that part having been inflamed from a cold, 

 and injudiciously treated. Such cases are, however, quite 

 exceptional. 



VI. Youatt demonstrated in 1833 that roarers are usually 

 affected with atrophy of the muscles of the larynx on the 



