ROARING. 47 



cous membrane lining the air-passages, and that the ordinary 

 consequence of their virulence or long continuance is — 



Thickening of the membrane, with occasional ulcera- 

 tion of it ; and this it is that appears to constitute, in young 

 horses, the ordinary cause of roaring. How many three and 

 four-year-old horses are there passing from the dealer^ s or 

 breeder's hands into stables, who, soon after their arrival 

 therein, — particularly if it should be in the spring or autumnal 

 season, — breed strangles or distemper, or else contract cold 

 and sore throat, any of which disorders, in a severe form, 

 settling upon the throat and windpipe, will be very apt to 

 lay the foundation for roaring, by leaving behind them a 

 thickened, perhaps an ulcerated condition of membrane, and 

 most likely at the part where it lines the glottis; though the 

 same may take place within the cavity of the windpipe. There 

 is likewise reason to believe that similar alterations of struc- 

 ture, even within the branches of the windpipe — the bronchial 

 tubes — may have the same effect in kind, if not in degree. 

 In the course of time, the thickened membrane is found to 

 undergo still further changes : from being simply thickened, 

 it turns opaque and white, and acquires a leathery, indurated 

 feel and texture — organic transformations which set all and 

 every kind of treatment completely at defiance. 



Ulceration of the membrane of the larynx, par- 

 ticularly of that part lining the glottis, is very apt to follow 

 an epidemic, or specific, or malignant inflammation of this 

 membrane ; and this ulceration will often assume a sort of 

 chronic inactive form, in which state I have had reason to 

 believe it has continued for years, or even to the end of the 

 animaFs life. This it is that has given rise to roaring 

 being said to be present in glanders. Such a case of 

 roaring, it is obvious, would require a treatment altogether 

 different from most others. 



Metastasis. — Any inflammation about the throat or its 

 vicinity, by extending to or settling upon the larynx or 

 windpipe, may in the end be productive of roaring. In 

 illustration of this, I quote the following : — 



The late Mr. Coward, V.S., Royal Artillery, had, in a 



