60 MR. youatt’s veterinary lectures. 
Generally speaking, however, although the inflammation is 
now approaching the chest, its extension into the trachea is not 
an unfavourable symptom. It covers a more extended surface, 
and is not so intense or untractable ; it is involving a part of 
the frame less complicated, and where less mischief can be ef¬ 
fected. True, if you neglect the case, it is shewing a disposition 
to spread that must terminate fatally; but it is coming more 
within your reach, and more under your command, and, the 
proper means being adopted, the change is rather a favourable 
one. 
The disorganizations produced in the trachea are similar to some 
which I have described in the larynx. The same formation of 
organized bands of coagulated lymph, the same thickening of 
membrane, diminution of calibre, and foundation for roaring. 
Roaring. 
This will be the proper place to speak of that singular impair¬ 
ment of the respiratory function recognized by the name of roar¬ 
ing. It is an unnatural, loud, grunting sound made by the 
animal in the act of breathing in quick action, or on any sudden 
exertion. If the horse is briskly trotted on a level surface, and 
more particularly if he is hurried up hill, or if he is suddenly 
threatened with a stick, this peculiar sound will be heard, and 
cannot be mistaken. When dishonest dealers are shewing a horse 
that roars, but not to any great degree, they trot away gently, 
and, as soon as they are too far for the sound to be heard, shew 
off the paces of which the animal may be capable, and, on re¬ 
turning, gradually slacken their speed when they come within a 
suspicious distance. This is sometimes technically called ** the 
dealers’ long trot.” On carefully listening to the sounds it will 
appear that the roaring is produced in the act of inspiration, and 
not in that of expiration. 
It is Urisoiuidness .—Roaring is a very unpleasant thing to the 
rider, and it is unsoundness too. It is the sudden and violent 
rushing of the air through a tube of diminished calibre : and if 
the impediment, whatever it is, renders it so difficult for the air 
to pass in somewhat increased action, sufficient air cannot be 
admitted to give an adequate supply of arterialized blood 
in extraordinary or long-continued exertion. Therefore, as 
impairing the function of respiration, although, sometimes, only on 
extraordinary occasions, it is unsoundness. In as many cases as 
otherwise it is a very serious cause of unsoundness. The roarer, 
when hardly pressed, is often blown even to the hazard of suffo¬ 
cation. There are cases on record of his suddenly dropping and 
dying when urged to the top of his speed. 
