V ■ 13 
THE 
VETERINARIAN. 
VOL. XIII, No. 145.] JANUARY 1840. [New Scries, No. 85. 
ON ROARING. 
By W. PeRCIVALL, Esq., M.R.C.S., and Veterinary Surgeon to 
the Regiment of Life Guards. 
ROARING is no more a disease in horses than crying is in 
ourselves. It is but a symptom, and of itself so vague a one, that, 
without much careful investigation, it is often as difficult to say 
what disorder is producing it as to divine the cause of a person’s 
grief. 
Definition. —Roaring may be defined to be, breathing with a 
loud or unnatural sound, under exertion of any kind. 
The sound or noise emitted varies under different unnatural 
conditions of the air-passages, and also under different degrees of 
exertion to which the animal may be put. With a view of elu¬ 
cidating the first of these assertions, I shall relate an experiment 
I made some years ago, touching the constriction of the windpipe. 
The second assertion rests upon facts known, I believe, to most 
experienced horsemen ; viz. that roarers made to gallop very fast 
become whistlers; and, pushed to their utmost speed, lose even 
their whistling noise. These varieties in the sound or roar” 
have given rise among horse-people to the epithets, grunters,” 
wheezers,” “ whistlers,” “ high-blowers,” “ trumpeters,” &c. 
The experiment I made is this:— 
I passed a ligature of broad tape around the windpipe at about one-third 
of the length of the neck from the head. The tape was at first drawn only 
moderately tight, and the animal roared when made to trot. Ne.xt, the pipe 
was compressed to about half its natural caliber: the animal then whistled. 
In both states the sounds emitted were found loudest in inspiration. At last, 
I drew the ligature as tight as I was able to do. In a minute afterwards, the 
animal, after staggering a good deal, fell down, struggled violently, and sud¬ 
denly throwing himself upon his side, expired in two minutes after he had 
fallen. I found the membrane lining the windpipe reddened, and covered 
with frothy mucus. The ligature had not completely obliterated the canal : 
I could still pass a crow-quill through the constricted part of it. 
VOL. XIII. A 
