116 
ON DISEASES OF THE LUNGS IN HORSES. 
state, unless immediately relieved, dies. This is not inflamma¬ 
tion, but is what is very apt to be followed by inflammation, sup¬ 
posing the animal to survive the original shock. 
Injuries, mechanical or chemical, may prove the cause of pul¬ 
monary disease. It is possible that the enveloping membrane, or 
even the parenchymatous substance, may suffer preternatural ex¬ 
tension and laceration from violent and convulsive efforts to breathe 
under certain bodily exertions, such as racing, leaping, plunging, 
&c. Contusions from falls or blows upon the side might injure 
the pleura; fractures of the ribs, or sharp instruments, may wound 
the pleura or lung. And as for injuries of a chemical nature, in 
this light may be viewed the several pollutions the atmosphere of 
the stable receives from the effluvia of the dung, the urine, and 
the breath of other horses. Ammoniacal gas is said to prevail in 
the effluvia from these excretions; and, therefore, there can be no 
question about the effects of such an atmosphere being highly 
excitant and creative of inflammation. 
DIAGNOSIS. 
In the study and observation of diseases of the pulmonary organs 
our chief aim must be to attain such intimate knowledge of them as 
will enable us not only to make the necessary distinctions between 
them, but to so far ascertain the nature of each as to render us com¬ 
petent to treat it to the best advantage, and at the same time give 
an opinion to be relied upon in regard to its result. Certain symp¬ 
toms are common to almost all these disorders: that, however, 
which is of all, if not the most common, the most important, is 
altered or disturbed respiration. And there are so many degrees 
and kinds of these alterations in the breathing, that they of them¬ 
selves, by attention on our part, may be rendered of great value to 
us in the formation of our diagnosis. 
Respiration in health is shewn by a placid, uniform, regular, 
and hardly perceptible motion of the flanks, at the rate, according 
to Delafond, of from 10 to 12 breathings a minute in young horses, 
from 9 to 10 in old; according to Professor Sewell, of from 4 to 8. 
If horses in the stable are referred to, I cannot but regard the 
latter standard as much too low. Delafond has given us what he 
calls a synoptical table of the different kinds of respiration,” from 
which we may gather some useful practical observations, without 
pretending to adopt all his finely-drawn distinctions. He makes a 
division of the different kinds of breathing, relatively, into 
1. Acceleration or retardation. 2. Depth of inspiration. 3. 
Difficulty of performance. 4. Modifications of these. 5. Accom¬ 
panying sounds or noises. 
Frequent Respiration is common to all pulmonary disorders 
