DYSPXCEA. 445 



lung-structiire. When tlie lining membrane of tlie chest is 

 affected we have a dry, short, painful cough. 



The spasmodic diagnostic cough of broken wind is dry, at 

 first paroxysmal, becoming in advanced cases solitary and 

 feeble. Associated with this cough, because often observed 

 as a distant precursor of it, is what may be termed the 

 ' nervous ' or ' intermittent ' cough. It is dry, hard, irritating, 

 and characterized by its sudden appearance without assignable 

 cause, and as unaccountably disappearing, to return at some 

 rather distant period. 



3. Dyspnoea. — Difficulty or oppression in breathing is fre- 

 quently enough brought under our notice, and although in 

 the horse this is oftener directly associated with changes occur- 

 ring in the respiratory organs than any other situation, it is 

 nevertheless a complex phenomenon, largely dependent on 

 other causes. As observed by us, it is usually connected with 

 — (a) Obstruction to the entrance of air into the respiratory 

 organs, whether occurring in the upper or lower part of the great 

 air-tube or its minute ramifications. This obstruction may be 

 the result of occlusion, more or less extensive, of any of the air- 

 conduits by a foreign body ; it may follow pressure exercised on 

 these by encroaching growths, or it may be dependent on spas- 

 modic closure, (b) It may follow destructive changes of the 

 pulmonic tissue, air-cells or air-tubes, or both, by which the 

 amount of breathing or aerating structure is greatly diminished, 

 as in consolidation, collapse, or compression, (c) Mechanical 

 and other interference with the expansibility of the chest- 

 wall may operate in a similar manner. (cT) An improper or 

 imperfect condition of the inspired air. (e) A pulmonic blood- 

 supply, defective or irregular in amount, impure or im- 

 poverished in quality. 



In all cases of oppressed and difficult breathing we have 

 placed before us for determination the causes of the impedi- 

 ment, and the means to be adopted for its removal. To a 

 solution of these we are directed by a careful observation of 

 such phenomena, and their modes of development, as the 

 entrance of air into the lungs, whether carried out freely or 

 with difficulty ; the existence or non-existence of noise during 

 the accomplishment of the act, Avhether the dyspnoea is con- 

 stant or only paroxysmal ; if there are any symptoms of blood- 



