CHRONIC DISEASES OF THE ORGANS OF RESPIRATION. 231 



a larger portion than natural of the air remains in the cells, even after 

 the intercostal muscles have performed their duties in the ordinary 

 course of expiration. In order to expel it, the animal is then obliged to 

 bring into play the abdominal muscles as auxiliaries. Hence arises the 

 prominent sign of Broken Wind, namely a double action of the flanks. 

 These effects ensue equally, whether the paralysis of the nerves be due 

 to previous inflammation of the lungs, or to indigestion. 



During catarrhal affections the disease is often temporarily increased 

 and also at sudden changes of the weather, especially during fogs and 

 easterly winds. 



In some cases Broken Wind is supposed to arise from a weakened 

 power in the diaphragm, in consequence of which the abdominal muscles 

 are called into play secondarily to assist in the act of expiration. 



467. Emphysema. 



Broken Wind is occasionally complicated with the condition known as 

 Emphysema. It consists in the retention in the inter-lobular cellular 

 tissue of the lungs of a portion of the air, which ought to be completely 

 expelled at each expiration. 



By some Veterinarians it has been supposed, that the inability to expel 

 the air is due to rupture of the coats of the air cells, on account of which 

 the air escapes either underneath the pleurae or into the substance of the 

 lungs. Post-mortem examination, however, generally fails to show any 

 such lesions. The retention of the air is more probably caused by 

 general weakening of the structure, owing to want of nervous power a 

 result of the later stages of the original disease. 



468. Treatment. 



The peculiar symptom of flatulence, which is present in every broken- 

 winded horse, shows pretty clearly that in the great majority of cases 

 the disease is due to disordered state of the digestive organs rather than 

 to previous disease of the lungs. 



As regards treatment in incipient cases, especially in those which 

 result from derangement of the stomach, there is reason to hope, that 

 removal of the causes and reversal of the conditions, which have induced 

 the malady, may check its progress, although we must not hope alto- 

 gether to get rid of the disease. Careful feeding and watering and 

 regular exercise are essential. 



But when Broken Wind has become chronic, whether it has arisen 

 from inflammatory attacks on the respiratory organs or from indigestion 

 or from emphysema, where in short any alteration has taken place in 

 the structure of the lungs, the disease is obviously incurable, and active 

 treatment is worse than useless. 



Relief, however, always follows any improvement in the hard condition 

 of the animal for work. But on the other hand it is not easy to get 

 into condition an animal with functional derangement of the lungs, and 

 perhaps a disordered stomach in addition. The best care, the greatest 



