DISEASES OF THE LUNGS 11 



ASTHMA 



Definition of Asthma. This is a diseased state of the lungs, marked 

 by paroxysms of difficult breathing and distress, accompanied by a wheez- 

 ing sound. It is believed to be due to spasmodic contraction of the 

 bronchial tubes, and from the peculiar suddenness of its appearance and 

 disappearance it partakes of the character of a nervous disorder. 



Causes. These are very obscure, but seem to be connected in some 

 instances with digestive disturbance, and by some authors are placed in 

 the category of diseases of the digestive system. In susceptible animals it 

 may be induced by breathing an atmosphere charged with irritating gases 

 and other impurities. Besides a vitiated atmosphere, it is sometimes 

 brought into existence by an attack of bronchitis, which is undoubtedly 

 a factor in its development. 



Symptoms. The attacks may come on so suddenly that warning 

 symptoms are brief, if at all observed. The breathing is at once difficult 

 and distressing, and the duration of the attack altogether uncertain. In- 

 spiration is less difficult than expiration, the latter being accomplished 

 with a double action of the flank, and the whole body receiving a distinct 

 jerk at the end of the movement. As compared with broken wind, which 

 in some respects it resembles, the symptoms are more paroxysmal and 

 acute, there is also greater distress, as evidenced by the anxious counte- 

 nance, and the short irritable cough, which returns again and again in 

 choking paroxysms. The discharge of small quantities of mucus as a 

 result of coughing, and more or less elevation of temperature and loss 

 of appetite, also serve to distinguish asthma from broken wind. Its sudden 

 appearance is as remarkable as its rapid subsidence, but in some cases, 

 after repeated attacks, it passes imperceptibly into that form of lung 

 disease, known popularly as " broken wind". The subject of asthma is 

 pretty sure of a recurrence of the affection at no very distant date. 



Treatment. An oily aperient, preferably linseed-oil, may be given 

 first, and followed at short intervals with fairly large doses of such sedatives 

 as chlorodyne, or camphor and belladonna, combinations of stimulants, 

 as nitrous sether and valerian, and failing early relief a change of sedatives 

 to chloral and the bromides of potassium and ammonium. Chlorodyne 

 is especially useful, and rather bold doses are found to be safe and speedy 

 in effect. All dry and dusty food should be removed, and no bulky 

 aliment allowed. Linseed, boiled or scalded, is found to be the best food, 

 and undoubtedly has a medicinal effect also. This, with a little bran 

 and scalded oats, should be given in small quantities, and often. Different 

 animals are differently affected by atmospheric conditions. Some experi- 



