38 
We shall shortly see that in some cases where heredity plays an activ 
part, chronic cough degenerates into roaring or broken-wind ; and for this 
very reason, if for no other, no horse affected with cough can during the 
continuance of the complaint be passed as sound. 
We will now turn to the consideration of grunting. If a horse when 
struck or suddenly moved, makes during expiration a grunting sound he is 
termed a grunter, The emission of this noise is always to be regarded with 
suspicion, as it generally accompanies whistling and roaring. It may or may 
not depend upon diseases of the upper part of the breathing tube. In some 
cases a horse may grunt from pain alone, when suffering from pleurisy or 
from a neuralgic affection of the respiratory muscles of the chest, called 
pleurodynia, and other diseases. Many cart horses and large horses of any 
breed are apt to grunt, being nevertheless perfectly sound in their wind; and, 
indeed, if fed for a time on heavy bulky food, any horse may become a 
grunter from this cause alone. If a grunter stands the tests used to detect 
roaring without making any noise in his breathing, he is, according to 
Professor Williams, and in the writers’ opinion also, to be considered as 
sound. 
Whistling is of two varieties, soft or moist, and dry or hard. The 
former occurs in acute inflammation of the larynx, when much exudation is 
thrown out in that structure, and also when the lining membrane is much 
swelled. In the first condition it is a wheezing noise, and is mostly 
diminished when the-horse coughs. In the second case it is louder during 
inspiration than during expiration. 
Soft whistling constitutes temporary unsoundness. It is in many cases 
unsafe to hazard a decided opinion for some days or even weeks, until the 
thickening of the lining membrane and the relaxed condition of the vocal 
cords have had time to regain their normal state. Dry whistling is, 
according to some authorities, to be regarded as a modification of roaring. 
Others, however (among whom is the writer), are of opinion that whistling 
and roaring are due to different states of the throat, and that they may exist 
independently of each other. Dry whistling, like roaring, is a sound made 
during inspiration. It is due to diminished calibre of the larynx, or 
sometimes of its continuation downwards, owing to thickening of the lining 
membrane, distortion of the neck through tight-reigning, the presence of a 
fixed tumour in the air tube, or any other cause which diminishes the size of 
the passage through which the air escapes to and from the lungs. Whistling, 
though loudest in inspiration, is by no means absent during expiration. 
Dry whistling, like roaring, is often traceable to hereditary influence, and it 
constitutes unsoundness. 
ROARING, 
ALTHOUGH few complaints of the horse are so well known as roaring, yet 
there are not many regarding the nature and cause of which more erroneous 
notions are generally prevalent. Roaring is a loud unnatural sound made 
