136 , 
SOCIETY MEETINGS. 
ASTHMA. 
Broken wind is the name commonly applied by horsemen to 
asthma, and since asthma is an exceedingly rare disease, this ex¬ 
pression is, when so generally applied, clearly a misnomer, and 
does not necessarily, nor scarcely ever, imply that the horse is 
suffering from asthma. When I state that it is rarely seen in 
the horse, it might be well to add that it frequently occurs in 
dogs. The object of this paper is to call the attention of the 
veterinary profession to the fact that under the present use of 
the term, “ broken wind,” other diseases are included which 
ought to be excluded, for the reason that from asthma they are 
readily differentiated. 
Amongst those diseases which are so apt to be confounded 
are pulmonary emphysema and “ roaring,” the latter term being 
simply symptomatic of some pathological lesion of the larynx, 
and sometimes of the trachea. Now, to my mind, there should be 
no difficulty, according to the morbid anatomy of these named 
conditions, in discriminating between them. 
In pulmonary emphysema, or “ heaves,” the lesion consists of 
an abnormal accumulation of air in the air cells and in the inter¬ 
lobular connective tissue, with a dilatation of the vesicles either 
with or without a rupture of their walls, and these walls ruptur¬ 
ing gives rise to that condition known as air sacs, which varies in 
size in accordance with the amount of tissue involved in the pro¬ 
cess; these conditions are known as vesicular and interlobular 
emphysema. Asthma is purely functional, viz.—a spasmodic 
contraction of the bronchial tubes, while emphysema is organic, 
having a structural change; yet these conditions may be asso¬ 
ciated with each other, still they are distinguishable, as asthma is 
a disease jper se. Literature on this subject leads us to suppose 
that in the past it prevailed extensively, but our experience at 
the present day does not bear this out. This great lessening of 
its frequency is undoubtedly due to the application of the prog¬ 
ress of the science, resulting in an elimination of heredity, liyge- 
nic surroundings and feeding, which enters so largely into its 
etiology. Asthma is a spasmodic contraction of the involuntary 
