ROARING. 487 
is not very severe ; but by confirmed roarers the slow work of the cart is 
all that can be performed without cruelty. 
Where paralysis of the muscles that open the rima glottidis is the seat of 
the roaring, no plan has yet been suggested which is of the slightest avail. 
In the first place, it is extremely difficult, and indeed almost impossible, 
to diagnose the affection, and I know of no means by which paralysis can 
be ascertained to exist during life. Hence, although it is barely possible 
that by the use of strychnine the nerve might be stimulated into a resto- 
ration of its functions, yet as the case cannot be ascertained, it is scaygely 
wise to give this powerful drug in the hope that it may by chance hit the 
right nail on the head. ‘This paralytic condition seems chiefly to attack 
carriage-horses, and probably arises from the pressure made by the over- 
curved larynx upon the laryngeal nerve as it passes through the opening 
in the thyroid cartilage. Many veterinary writers have looked to the 
recurrent branch of the par vagum to explain the loss of power, but 
I believe it is rather to the laryngeal nerve that the mischief is due. It 
must be remembered that carriage-horses are not only reined up for hours 
while doing their daily work out of doors, but they are also often placed 
in the same position, or even a more constrained one, by the coachman in 
the stable, in order to improve their necks. One horse of his pair 
perhaps has naturally a head better set on than the other, and he wishes 
to make nature bend to his wishes by compelling the other to do that 
which the shape of his jaw forbids without a sacrifice. The mouthing 
tackle is put on in the stable with this view, and the poor horse is 
“kept on the bit” for three or four hours early in the morning, during 
which time his larynx is pressed between his narrow jaws into a most 
unnatural shape. ‘The consequence is either that the nerve is pressed 
upon, and the muscles to which it is supplied are paralysed, as in the 
condition which we are now considering, or the cartilages are permanently 
disfigured, which is the subject of the next paragraph. When the paralysis 
is established, I believe no means but the internal use of strychnine are at 
all likely to be beneficial: 
An alteration in the shape of the cartilages, so as to permanently change 
their form, is, I believe, the least common of all the causes of roaring. 
Pressure for a very long time will be required to effect this, and far more 
than suffices to paralyse the nerve. Cases, however, are recorded, and the 
parts have been preserved, so that there can be no doubt of their occasional 
occurrence. No treatment can be of the slightest service. 
Although roaring, in all its varieties, may be said to be generally 
incurable, yet it may be greatly palliated by general attention to the state 
of the lungs and stomach, by proper food, and by the use, while the horse 
is at work, of a special contrivance, of a most ingenious nature, published 
by Mr. Reeve, of Camberwell, in the Veterinarian for 1858, but said to 
have been in use for many years among the London omnibus and cab 
men. At all events, Mr. Reeve deserves the credit of having laid the 
matter before the profession, and of explaining the true principle upon 
which it acts. He says, in his paper on the subject : “I thought it pos- 
sible to so modify the atmospheric supply to the lungs, that, during 
exercise, the volume of air, when it arrived at the glottis, should not 
exceed that which passed through its opening when the horse was tran- 
quil, and which (from the fact of the sound being absent) does not at that 
time produce roaring. A strap was accordingly made to pass around the 
nose of the horse, just over the region of the false nostrils, and buckle 
beneath the lower jaw. To the inner surface of this strap, and imme- 
