SPASM OF THE DIAPHRAGM. 123 



CHAPTER XIX. 



SPASM OF THE DIAPHRAGM. 



This disease is introduced here because it may be 

 confounded with carditis, and should be carefully 

 distinguished from it. 



Let it be supposed that a horse a little out of con- 

 dition, and perhaps with a full stomach, has been 

 ridden far and fast. He is pushed onward after he 

 has shown symptoms of distress ; or his own courage 

 carries him forward until he comes to a perfect stand- 

 still ; then, or soon afterwards, the following symp- 

 toms appear : he stands with his legs fixed ; his neck 

 stretched out; his nostrils expanded to the utmost; 

 every limb trembling; the flanks heaving, and the 

 countenance exhibiting anguish ; there is seen, at the 

 same time, a convulsive jerking similar to that which 

 has been described under the head of carditis; the 

 thumping noise which accompanies disease of the 

 heart is also heard, only louder and more marked. 



An inexperienced person might confound this with 

 carditis ; and he would set to work to bleed the horse ; 

 and as surely as he did so he would destroy the ani- 

 mal. Although this sound is heard from the chest, 

 the heart has little to do with it. It is spasmodic 

 action of the diaphragm. 



The diaphragm is one of the agents in respiration ; 

 it acts principally when the breathing is quiescent; 

 but has had more than its usual share of labour to per- 

 form during the late exertion because the system was 

 exhausted. The diaphragm however continued its 



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