68 
ON ROARING. 
By W. Sewell, Esq. Assistant Professor. 
Symptoms .—In the incipient stage, the impediment is so slight 
as to cause a wheezing in violent exercise, particularly in deep 
ground, where strong muscular exertion is required in progression. 
The terms piping and whistling are all modifications of the same 
disease. The only way to ascertain the existence of the disease 
decisively, is by exertion. The sound of the cough excited by 
squeezing the trachea is often sufficient, and cannot easily de¬ 
ceive the experienced practitioner. 
In a draft horse it may be ascertained by putting him into 'har¬ 
ness, and obliging him to draw a heavy load. The tracheas of 
old horses that are roarers are frequently so rigid as to be inca¬ 
pable of being squeezed with safety to such a degree as to ex¬ 
cite coughing: this rigidity is often, of itself, a sufficient proof to 
the practitioner. 
Causes .—When it takes place in colts that have not been bro¬ 
ken or regularly domesticated, it is usually the result of severe 
cases of strangles that have not terminated favourably, but left 
a thickening, and often chronic ulceration, of the mucus men- 
brane lining the larynx : in others, it is preceded by severe 
colds and sore throats, producing similar lesions of structure : 
the latter cause is frequently the origin of roaring in all kinds of 
horses ; and in all unhealthy seasons, in spring especially, the 
disease has its origin. 
The last spring and summer, which were particularly unhealthy 
to horses, produced an unusual number of cases. 
The restraint to which young horses are subjected in breaking 
is another frequent cause, by bending the nose inward upon the 
neck, when on the bit in stalls, or at work in the lounge or break, 
and by dumb jockeys or crosses. The windpipe is thereby con¬ 
tracted, curved, and shortened in its length : the ligaments, na¬ 
turally elastic, lose their action, and become rigid, deforming and 
destroying the functions of the organ considerably : this is again 
aggravated, and rendered incurable in old horses, by the ossifica¬ 
tion which takes place in consequence of the continuance of the 
practice of hard reining up, as it is termed, but is, in fact, rein¬ 
ing in. 
Neck straps, improperly applied for various purposes, occasion 
roaring. Collars worn too high would do the same. Fractures 
of the trachea from blows have at times occasioned it, by depress- 
