HIPPO-PATHOLOGY. 
tend to shorten or impair the animal’s wind. Roaring and thick 
wind commonly have their foundation laid in bronchitis. The 
bronchial membrane during the early stages of disease will be 
found in a state of congestion or turgescence ; in the sequel it is 
very likely to become thickened in substance — hypertrophied, as it 
is called — -in which condition the calibre of the bronchial tubes, 
the small ones in particular, will suffer considerable diminution, and 
consequently become but comparatively imperfect conductors of the 
respired air. In the larger tubes the lining membrane is furnished 
with follicles ; and, in fact, has the true mucous character ; but in 
the very small ones, as we approach the air-cells, it has been found 
to bear more similarity to a serous membrane, and on this account 
becomes still more disposed to take on the plastic or adhesive kind 
of inflammation, which not only gives rise to hypertrophy, but 
occasionally to solid effusion and agglutination of the sides of the 
tubes, obliterating their cavities, and converting them into mere 
chords, the same as happens when inflammation is set up in the 
interior of bloodvessels ; and this may even go so far as to block up 
and annihilate the air-cells. The effect of this will be to shorten or 
“ thicken” the wind, to compensate for which the animal will make 
additional efforts in respiration, and the result is likely to be dilata- 
tion of the vicinous tubes and air-cells. It would appear that this 
process of obstruction commonly commences in the smaller and 
makes way into the larger tubes, and from the circumstance of 
secretion having been found pent up in the air-cells while the 
tubes were in a state of obliteration, and assuming that sort of 
aspect which tubercles and vomicae are known to give the lungs, 
Mr. Stokes* has ingeniously hinted that this “ will go far to clear 
up the controversy about the nature and origin of tubercles.” In 
acute attacks of pure bronchitis in young and otherwise healthy 
horses, dissection has brought nothing to light but a reddened and 
turgescent or thickened state of the bronchial membrane, the tubes 
themselves being filled with a quantity of frothy mucus, appearing 
as if the animal had been actually choked by it, or, as Dr. Elliot- 
son has pertinently expressed it, “ drowned inwardly by mucust.” 
TREATMENT. — Although blood-letting is the remedy upon which 
our chief reliance must be placed for the cure of bronchitis in its 
acute form, yet it is one I do not recommend the practice of in mild 
cases, nor even in others until the disease has quite set in. I do not 
find that its very early employment tends much to shorten or mitigate 
bronchitic affections ; although it becomes highly serviceable as soon 
as the disorder begins to manifest any severity ; and whether we 
bleed in the very beginning or not, we shall certainly be compelled 
* In his “ Treatise on Diseases of the Chest.” 
f Dr. Elliottson’s Lectures. 
