70 Roaring in Horses. 



greatly assist, under ordinary circumstances, in the detection 

 of Roaring. 



When noisy respiration is due to nasal obstruction, the 

 sound is usually heard in expiration as loudly as in inspi- 

 ration, and is of a snoring character; it may come from 

 only one nostril, or if from both it is then unequal in 

 intensity, as is also the volume of air entering and leaving 

 them. Injuries to, and deformities of, the trachea can 

 generally be discovered by palpation ; auscultation will 

 also distinguish their seat if they obstruct the breathing. 

 In cases of tumour in the trachea, the noise is usually more 

 pronounced during expiration, as the tube then contracts, 

 while in inspiration it dilates. In cases of chronic laryn- 

 gitis {laryngitis chronica fibrosa) observed by Moeller, there 

 was greater resistance in the larynx on attempting to squeeze 

 it, but the inspiration could not be rendered noisy by 

 moderate pressure on the arytsenoid cartilages of either 

 side. The expiration is also as noisy as the inspiration. 



As has been already mentioned, swellings in the vicinity 

 of the larynx may cause a noise in respiration ; even slight 

 congestion of the vocal cords may produce Eoaring. 

 Giinther gives an instance in which distention of the 

 laryngeal ventricles with pus caused sonorous breathing ; 

 the sound ceased when the fluid escaped by depression 

 of the head. Mceller also mentions a case in which a large 

 collection of pus in one of these pouches dragged the 

 larynx to one side, and occasioned noisy respiration. 



Chronic Roaring can scarcely be confounded with em- 

 physema of the lungs (" broken wind "). The hurried 

 breathing in the former, after active exertion, is very differ- 

 ent to that observed in the latter condition. In lung 

 emphysema, the respiration, as observed at the flank, is 

 altogether peculiar and characteristic, and the sound has no 

 relation to the inspiration noise of Roaring. Indeed, horses 

 affected with Roaring are rarely broken-winded, as difficult 

 inspiration is far less likely to cause emphysema of the lungs 



