Symptoms and Diagnosis of Chronic Roaring. 67 



by a forcible expiration of air through relaxed vocal cords, 

 not in inspiration, as in Roaring. 



In connection with the cough, it may be noted that the 

 neigh of a horse which is a Roarer is modified in the same 

 way as the cough. 



Diagnosis. 



In alluding to the principal indications which enable us 

 to distinguish Roaring due to laryngeal paralysis from 

 noises produced by other causes, the measures necessary 

 for arriving at a conclusion with regard to the existence of 

 this condition must also be referred to. 



The chief symptom, and by far the most distinctive, is 

 the inspiratory sound in breathing. I have mentioned 

 the circumstances in which this is produced when due to 

 paralysis of the larynx. Experts, when examining horses 

 to detect the existence of the morbid condition, resort to 

 various tests. These are moving, exciting, and " coughing " 

 the horse. Manipulation and auscultation are also re- 

 sorted to. 



The most certain way to detect whether a horse is 

 affected with laryngeal paralysis, and also to ascertain the 

 stage which the disease has reached, is undoubtedly to 

 make the animal exert itself The amount of exertion 

 necessary to develop the characteristic sound, and the in- 

 tensity and nature of this, as well as the amount of dyspnoea, 

 are the criteria as to the presence and extent of the morbid 

 state. 



For riding-horses, the best test is speed. On level, firm 

 ground the distance should be greater than on that which 

 is soft (as soft clay-land or a ploughed field) or ascending, 

 the object being to cause the animal to respire deeply and 

 quickly. 



Soft or sandy ground should be chosen, if possible, as on 

 it there is less noise from the horse's feet. The animal may 



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