104 Roaring in Horses. 



strangely escaped the investigation of veterinary writers 

 until lately. For instance, Williams asserts that " dissec- 

 tions have failed to discover any change in the nerve-trunk 

 itself, although the animals dissected have been confirmed 

 Roarers for years previous to their death. In the form of 

 disease involving the laryngeal muscles, which commonly 

 causes Roarinsf, there is no chanofe in the nerve itself."^ 



The effect of these anatomical changes on the respiratory 

 act will be examined when we come to inquire into the 

 immediate cause of Roaring. 



Course of Roaring. 



Considering Roaring to be produced by morbid conditions 

 having a neuropathic origin, we will now glance at its course, 

 anatomically and clinically. 



The course of the defect — as every experienced veterinary 

 surgeon and horseman knows — varies within wide limits, 

 sometimes proceeding rapidly from an almost imperceptible 

 sifflement to a screaming sound, with urgent dyspnoea on 

 the horse being subjected to only moderate exertion. In 

 other instances, it increases slowly until it reaches a certain 

 degree, and then remains stationary for a long time — per- 

 haps for years, varying only slightly and temporarily, 

 according to the condition of the animal or surrounding 

 circumstances. In rare cases, the noise, after continuing in 

 a more or less notable degree for some time, spontaneously 

 disappears, and the horse is again sound, so far as its breath- 

 ing is concerned. Of this there are many instances, but 

 perhaps the most remarkable is that of the race-horse 

 Brigantine, one of the best of what were, in their time, 

 called the "Buccaneerids" — a rather renowned family. Her 

 own trainer vouched for the fact, which was otherwise well 

 known, that the mare began her racing career in a very 

 promising manner as a two-year old, but ran badly at a 



1 " Principles and Practice of Veterinary Medicine," pp. 509, 510. 



