tut: 
VOL. XIII, No. 146.] FEBRUARY 1840. [New Series, No. 86. 
ON ROARING. 
By W. Percivall, Esq., M.R.C.S., and Veterinary Surgeon to 
the \st Regiment of Life Guards. 
[Continued from p. 9.] 
DEFORMITY OF the Larynx or Windpipe, by which 1 
mean original malformation of them, is included by the French 
veterinarians among the causes of roaring. I do not remember 
ever having met with a case of the kind myself; though I once 
saw a preparation which gave me great reason for believing that 
the canal of the windpipe might be mis-shapen even from birth. 
It w'as a wet preparation. The canal of the windpipe, instead of being 
circular, was triangular, the sharp angle being turned forwards. Behind, the 
flaps of the rings of the pipe overlapped one another much beyond what was 
natural. The lining membrane was thickened throughout its extent. 
Mechanical Obstruction proves an occasional cause of 
roaring. A tumour of any sort, or any foreign bod}', pressing 
against the air-tubes, or forming within their cavities, may, (dthcr 
of them, be productive of roaring. 
The Head may be the Seat of Roaring. —My old friend 
and school-fellow, Mr. James Turner, in 1837, sent a paper to 
The Veterinarian, the product of very accurate ol)servation of 
a decided case of roaring in a horse sent to his Infirmary to be 
destroyed on account of lameness. 
Having completely satisfied himself of the existence of the disorder—the 
noise made being “ precisely that of a common roarer,”—and in one of its 
most aggravated forms,—he very carefully examined the lary nx, trachea, and 
lungs, after death, without arriving at the cause, which at length was disco¬ 
vered to be in the head. “ 'The right anterior and posterior turbinated bones 
were enonnously enlarged,”—“ dilated,”—“ not distended by any accumulated 
contents.” “ Upon attempting to pass my finger,” continues Mr. 'P., “ down 
the passage through the palatine arch, as a sound or a probe, it was ojiposcd 
by the turbinated bones being almost in contact with the septum, owing to 
their dilatation.” Subsequent drying of the head sliewed that that which in the 
recent state had appeared like enlargement or exostosis, was “ owing simply 
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