DISEASES OF THE HEART 457 



dilation of blood through the lungs; anything which leads to excessive 

 contraction of the right ventricle, by which the blood is forced into the 

 lungs directly, or any interference with the action of the left side of the 

 heart arising from deficient contractile power or mechanical obstruction in 

 the passage of blood through the left auricle or ventricle, would naturally 

 induce a state of engorgement of the vessels, or congestion of the lungs, 

 which would be indicated by symptoms which the veterinarian recognizes 

 without difficulty. The breathing would become rapid and oppressed, the 

 surface of the body would very quickly become cold, and from other signs 

 the examiner would very quickly diagnose congestion of the lungs. The 

 affection may be sufficiently severe to justify him in calling it pulmonary 

 apoplexy. Such a diagnosis would be in effect strictly correct, although it 

 may leave out of consideration altogether the real cause, viz. : the blocking 

 up of the vessels of the lungs with stagnant blood, not on account of any 

 derangement of the respiratory organs themselves, but entirely owing to 

 the circumstance that the heart is in such a condition that it is incapable of 

 carrying on the pulmonary circulation. 



It does not follow that the congestion of the lungs arising from defec- 

 tive action of the heart should take place suddenly to such an extent as 

 would lead to any serious disturbance in the breathing, or justify the 

 diagnosis of pulmonary apoplexy. Any mechanical difficulty affecting the 

 circulation of blood in the lungs, whether arising from some impaired 

 action of the heart or from any other interference, would lead to attacks of 

 difficult breathing, cough, sometimes rupture of small vessels followed by 

 bleeding from the nostrils, noises in respiration when it becomes at all 

 hurried, sudden attacks of spasm, and in some cases a condition- of the 

 breathing which may lead to the impression that the horse is suffering 

 from broken wind. Attacks of indigestion, and even gradually increasing 

 emaciation, representing that state of the system which is expressed by the 

 horseman's term " bad condition ", are all indications which may be really 

 consequent upon functional or structural derangement of the heart, al- 

 though there may be no symptoms which specially direct attention to it. 



As disease advances, more striking symptoms become evident. The 

 wasting may be associated with dropsical effusions in the lower extremities 

 and also along the inferior part of the abdomen, and there may be also 

 more serious forms of dropsical effusion into the heart-sac (pericardium), 

 the cavities of the chest, and abdomen. Chronic derangement in the 

 central organ of circulation also leads to nervous derangement, in which 

 the brain is commonly implicated. In the human subject, under these 

 circumstances, the symptoms are easily recognized. The patient complains 

 of frequent or even constant headache, with a feeling of fulness and heat 



VOL I 31 



