6 
ON ROAllING. 
Roaring is not a Disease, but a Consequence of Dis¬ 
ease —of catarrh, strangles, influenza, laryngitis, bronchitis: to 
which Hurtrel D’Arboval has added, pleurisy and peripneumony. 
Now, let it be observed, that these are all inflammatory diseases of 
the mucous membrane lining the air-passages, and that the ordi¬ 
nary consequence of their virulence or long continuance is 
Thickening of the Membrane, with occasional ulceration of 
it; and this it is that appears to constitute in young horses the 
common 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 dis¬ 
orders, in a severe form, settling upon the throat and windpipe, 
will be very apt to lay the foundation for roaring, by leaving be¬ 
hind them a thickened, and perhaps an ulcerated, 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 also 
reason to believe that similar alterations of structure, 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 transmu¬ 
tations which set all and every kind of treatment completely at 
defiance. 
Ulceration of the Membrane of the Larynx, particu¬ 
larly of that part lining the glottis, is very apt to follow an epi¬ 
demic, 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 animal’s life. Such a case of 
roaring, it is obvious, would require a treatment altogether differ¬ 
ent from most others. 
Metastasis. —Any inflammation about the throat or its vicinity 
may, by extending to or settling upon the larynx or windpipe, in 
the end be productive of roaring. In illustration of this, I cite the 
following :— 
The late Mr. Coward, V.S., Royal Artillery, had, in a horse of his own, the 
simple operation of bleeding succeeded by extensive tumefaction and suppu¬ 
ration of the jugular vein ; and this followed by abscess of the parotid gland, 
disease of the larynx, and permanent roaring. 
Bands of coagulable Lymph effused into and running 
across the cavity of the windpipe constitute another source of 
roaring ; but, I believe, a very rare one. The inflammation is the 
