done, the flank falls, or the abdominal muscles 
relax with a kind of jerk or spasm.” A sudden 
falling of the flanks indicates that the air is very 
readily inhaled; and a long continued exertion 
of the abdominal muscles shows that it is slowly 
and with great difficulty expelled. 
The veterinary surgeons of the last century 
appear to have generally regarded broken-wind as 
an undue enlargement of the lungs, and a loss of 
their elasticity. Lawrence, in particular, taught 
that the most common appearance of the lungs 
in broken-winded horses, is a general thickening 
of their substance, by which their elasticity 1s in 
a great measure destroyed, and their weight spe- 
cifically increased, at the same time that their 
capacity for air is diminished. Gibson thought 
that, in consequence of a hasty or injudicious 
feeding of young horses, the growth of the lungs 
and all the contents within the chest are so in- 
creased as not to have space within the cavity of 
the chest for the full play of their parts, or the 
free performance of their functions. “ A narrow 
contracted chest, with large lungs,” says another 
writer of last century, ‘may sometimes naturally 
be the cause of this disorder; and it has been 
observed that horses rising eight years old, are 
as liable to this distemper as, at a certain period 
of life, men fall into asthmas, consumptions, and 
other chronic diseases. The reason why this 
disorder becomes more apparent at this age, may 
be, that a horse comes to his full strength and. 
maturity at this time; at six, he commonly 
finishes his growth in height; after which, he 
lets down his belly, and spreads, and all his parts 
are grown to their full extent; so that the pres- 
sure on the lungs and midriff is now more in- 
creased. But how little weight soever these rea- 
sons may have, repeated dissections have given 
ocular proofs of a preternatural largeness, not 
only of the lungs of broken-winded horses, but of 
their heart and its bag, and also of the membrane 
which divides the chest, as well as of the remark- 
able thinness of the diaphragm or midriff. This 
disproportion has been observed to be so great, 
that the heart and lungs have been almost of 
twice their natural size, perfectly sound, and 
without any ulceration whatever, or any defect 
in the windpipe or its glands. Hence it appears 
that this enormous size of the lungs, and the 
space they occupy, by hindering the free action 
of the midriff, is the chief cause of this disorder ; 
and as the substance of the lungs was found 
more fleshy than usual, they must of course have 
| lost much of their spring and tone.” 
But though the lungs of a broken-winded horse 
are larger than their natural size, they appear to 
acquire the chief feature of their disease from a 
ruptured condition of some of their air-cells. 
“Numerous air-bladders occurred on the surface 
of all which were examined by Mr. White; and 
these, he thinks, “must have arisen from a rup- 
ture of some of the air-cells, for in that case 
some part of the air which is inspired will neces- 
BROKEN-WIND. 
045 
sarily get into the cellular membrane of the 
lungs, and diffuse itself until it arrives at the 
surface, when it will raise the pleura so as to 
form the air-bladders we observe.” Mr. Youatt 
also states that, “in almost every broken-winded 
horse which he has examined after death, he has 
found dilatation of some of the air-cells, and par- 
ticularly towards the edges of the lobes. There 
has been rupture through the parietes of some of 
the cells, and they have evidently communicated 
with one another, and the air could be easily 
forced from one portion of the cells to another. 
There was also a crepitating noise while this 
pressure was made, as ifthe attenuated mem- 
brane of some of the cells had given way. These 
were the true broken cells; and hence the deri- 
vation of the name of the disease.” 
One cause of broken-wind is constitutional or 
hereditary tendency to contract inflammatory 
affections. Another cause is the particular kind 
of organic conformation, such as narrowness of 
chest or fragility of membrane, which offers most 
resistance to a free expansion and a full play of 
the lungs. Another cause, or rather introduc- 
tion and almost begun formation, is the disease 
of thick-wind. A fourth cause is plethora or 
fulness of habit, occasioning an undue determi- 
nation of blood to the lungs, an increase of the 
secretions within the air-vessels, and perhaps the 
production of acrimoniousness and viscidity in 
these secretions. But a more frequent cause 
than any, and one which reflects vast censure upon 
owners and keepers of horses, is violent exercise 
while the stomach is distended with water, but 
especially with dry food. “ Horses that are 
greedy feeders, or devour large quantities of 
slightly nutritious food, or are worked with a 
stomach distended by this food,” says Youatt, 
“are very subject to broken-wind. More depends 
upon the management of the food and exercise 
than is generally supposed. ‘The post-horse, the 
coach-horse, and the racer, are comparatively 
seldom broken-winded. ‘They are fed at stated 
periods on nutritious food that lies in little com- 
pass, and their hours of feeding and of exertion 
are so arranged that they seldom work on a full 
stomach. ‘The agricultural horse is too often fed 
on the very refuse of the farm, and his hours of 
feeding, and his hours of work, are frequently ir- 
regular; and the carriage-horse, although fed on 
more nutritious food, is often summoned to work 
by his capricious master, the moment his meal is 
devoured. A rapid gallop on a full stomach has 
often produced broken-wind.” 
A thorough knowledge of the nature and causes 
of broken-wind is of great importance to every 
farmer; for, while the disease is both very com- 
mon and very serious, the only effective means 
of dealing with it is prevention. Broken-wind 
might, in the great majority of instances, be fully 
and easily prevented; but, when once formed, it 
can never be cured. Yet, in all its ordinary 
forms, it may be considerably alleviated. When 
2M 
I 
