CHAPTER Y. 



SYMPTOMS AND DIAGNOSIS OF CHKONIC ROARING. 



Percivall long ago remarked that the term ' Roaring ' is 

 rather a generic than a specific one ; and I have already men- 

 tioned that it does not indicate a disease, but only a symptom 

 of a morbid condition of the air-passages of the horse. To 

 speak of the symptom of a symptom is therefore absurd, 

 and would be inexcusable here, had not universal custom for 

 years caused the symptom to be regarded as the disease 

 itself, and it has been written and spoken of accordingly by 

 horsemen and veterinarians. It will therefore be understood 

 that, when treating of Chronic Roaring, the signs described 

 are those which characterize the condition that in nearly all 

 cases gives rise to impeded and noisy respiration — viz., 

 paralysis of the muscles on the left side of the larynx. 



This condition I have ventured to designate "Laryngismus 

 paralyticus," as conveying, technically, an idea of the altered 

 state of that organ, and the cause which produces the con- 

 striction of its passage. Professor Moeller has named it 

 "Hemiplegia laryngis," which only partially defines the 

 condition ; and others have termed it " Laryngismus 

 stridulus," a designation applied to the ephemeral and 

 spasmodic laryngeal disorder commonly known as whooping- 

 cough in mankind, and therefore misleading as referring to 

 the laryngeal constriction (or stenosis) due to paralysis of 

 that organ in the horse. 



The chief symptoms of paralysis of the muscles of the 

 larynx in the horse are : 1. The noise (stridor) emitted in 



