THE 
VETERINARIAN. 
VOL. \ I, No. 68.] AUGrXJSX, 1833. [New Series, No. 8. 
MR. YOUATT’S VETERINARY LECTURES, 
DELIVERED AT THE UNIVERSITY OF LONDON. 
LECTURE XXXI. 
Chest Affections in the Horse. 
I HAVE hinted at the disadvantage under which the veteri¬ 
nary surgeon labours in his treatment of the diseases of the 
chest, and particularly in the horse. He must not only subdue 
the malady, but he must remove all its consequences. He must 
leave his patient perfectly sound, or he has done comparatively 
nothing. This is a task alw^ays difficult, and sometimes impos¬ 
sible to be accomplished. The tw^o most frequent consequences 
of severe chest affections in the horse are recoD;nized under the 
terms thick wind and broken luind. The breathing is hurried in 
both, and the horse is generally much distressed w’hen put upon 
his speed ; but it is simply quick breathing in the first, with a 
peculiar sound like half roaring; the inspirations and expira¬ 
tions are rapid, forcible, but equal : in the second the breathing 
is also hurried, but the inspiration does not differ materially 
from the natural one, while the expiration is difficult, doubly 
laborious. The changes of structure wdiich accompany these 
states of morbid respiration, are as opposite as can be imagined. 
Indumtion of the substance of the lungs, diminution of the 
number or the calibre of the air-passages, are the causes of 
tkick~wind. If the portion of lung employed is lessened, or the 
bronchial tubes will not admit so much air, the quick succession 
of efforts must make up for the diminished effect produced by 
each. In broken wind there is rupture of the air-cells, there is 
an unnatural inter-communication between the air-cells in the 
same lobule, or between those of the neighbouring lobuli. It is 
no longer, if we may dare so to consider it, a rounded cell with 
one opening into it, through wffiich the air will easily pass during 
the expansion or contraction of the cell; but the membrane be¬ 
tween the cells being ruptured, a kind of labyrinth is formed, in 
which the air becomes entangled, and from which it is impqssi- 
VOL. vi. 3 F 
