PECULIAR TO nOKSES. 119 



brane lining the npper portion of tlie respiratory passage ; and when 

 roaring is occasioned by thickening of this membrane, its degree 

 depends on the ratio of decrease in tlie calibre of the tube breathed 

 through. 



Roaring is a very aristocratic disease. Many of the very best and 

 fastest horses in England were, and now are, notorious roarers. Fly- 

 ing Childers, as fast a horse as ever wore liorse shoes, was one of 

 the worst roarers ever known. The story runs, that when Childers 

 was at full speed, liis roaring resembled juvenile thunder! — he could 

 be heard when distant haif a mile ! 



The worst fnrm of roaring (as paddy says) is ifhiatUng. This is 

 the sharp, shrill note, not only occasioned by the thickening of the 

 lining membrane of the primary passages of respiration, but by alter- 

 ations in the form and structure of the larynx — the larynx being, in 

 popular language, known as the " voice box." 



Roaring is more prevalent among stallions than mares and geld- 

 ings ; and the kind of horse most subject to it is the one having a 

 thick, chunky neck, and having the angles of the jaws in very close 

 proximity with the neck. 



Roaring, scarcely, if ever, admits of a radical cure, and when of 

 hereditary or congenital origin, a cure is impossible. A roarer should 

 never be encumbered with a check-rein, for it has the effect of caus- 

 ing undue pressure on the larynx, and thus augments the difficulty. 



Roaring can, however, be relieved by an operation known as 

 tracheotomy, which is performed at a point a few inches below the 

 larynx. 



At a late meeting of the Imperial and Central Society of Veteri- 

 nary Medicine, M. Leblanc read a communication on tracheotomy 

 which was performed on a carriage horse. " The operation had been 

 performed because the horse was a severe roarer, and he wore the 

 tube eighteen years and a half, doing fast work all the time. The 

 animal was destroyed at t^venty-three years of age, the owner not 

 desiring to make further use of him, nor to sell him. Since the op- 

 eration, Leblanc had not observed any change in the horse, except 

 a depression of the bones of the face. After death, the larynx was 

 found very narrow, the mucous membrane and sub-mucous cellular 

 tissues were thickened, the epiglottis deformed, very obtuse, and 

 averted at its free margin. The change in the larynx was the orig- 

 inal cause of roaring. The depression of the bones of the face was 

 connected with constriction of the nasal chambers, and was evidently 

 secondary to the change in the course of the air in the process of 

 respiration. The parts of the trachea in contact with the tube had 

 undergone a transformation into very hard tissue, which replaced 

 both mucous membrane and cartilaginous tissue. It filled the tracliea 

 above the point where the tube had been introduced, and, intermixed 

 with this firm, fibrous deposit, was cartilaginous and osseous tissue, 

 whicli oflbred great resistance to the scalpel." 



Roaring, thick wind, whistling, &c., are often the sequel of stran- 

 gled infiuonza, laryngitis, and other affections of the respiratory pas- 

 sages, and hence may have an accidental oi'igin; in such cases we 

 may entertain a hope of doing some good by means of medicinal 

 agents and counter-irritants. 



