213 
ON SOME OF THE DISEASES OF THE RESPI¬ 
RATORY ORGANS OF THE HORSE AND 
OTHER ANIMALS. 
By Professor Brown, M.R.C.V.S., London. 
(Continued from p. 81.) 
BRONCHITIS. 
More frequently, perhaps, than any other of the lung 
structures the mucous membrane is the seat of disease; the 
various forms of catarrh confine themselves to this tissue, 
and inflammation also seems to attack it more commonly 
than the serous membrane or parenchyma. It has been 
already noticed that catarrh will extend to the bronchial 
tubes, constituting bronchial catarrh; between this condition 
and that of inflammation there is, however, a distinction to 
be made. So long as catarrh alone exists, there are no 
active symptoms, no excitement of circulation nor respi¬ 
ration; there maybe painful cough, much prostration, and 
occasional disturbance of breathing from mechanical obstruc¬ 
tion, but no indications of actual inflammation; in bron¬ 
chitis, however, both the circulation and respiration are 
of necessity accelerated. The disease may be of the low 
form, and as much debility be present early in the disease 
as in the epidemic catarrh or influenza. 
Causes acting apparently under precisely similar condi¬ 
tions seem to produce very various consequences. Two 
animals, exposed to exactly the same influences, shall suffer 
differently, one perhaps from acute pulmonary congestion, 
the other from a simple cold. So, in the same manner, the 
ordinary causes of cold will in certain instances result in 
bronchitis. 
Some peculiarity of constitution, something which is 
conveniently called idiosyncrasy, must be assumed to explain 
this; or, in plainer terms, we must accept the fact as it 
occurs, without in the present state of our knowledge being 
able to explain it at all. 
In the preliminary remarks upon respiratory diseases, 
it was noticed how colds and influenza occur apparently 
independently of weather; the same is true of inflammatory 
affections. Some animals will suffer from an attack after 
a short journey, the body being heated by exertion as the 
