GENER.AJL SYMPTOMS AND FORMS OF CARDIAC; DISEASE. 549 



Many of these cases, while at rest in the stable, give little 

 indication of the extent of the cardiac mischief which exists ; 

 but Avlien put to work or rapid movement on unequal or heavy 

 ground, the dyspnoea may be so great as completely to inca- 

 pacitate for further progression until the cardiac oppression is 

 somewhat removed. 



Such animals are generally sufferers from valvular insuffi- 

 ciency of the right auriculo-ventricular opening, with dilata- 

 tion of the same side. Others, again, are disposed to exhibit 

 sjrmptoms of what are usually known as fainting-fits, syncope, 

 or vertiginous seizures. 



These attacks may be developed equally when the horse is 

 at rest and in the stable, as when at work — most probably of 

 more frequent occurrence in the latter condition. Even then 

 they may be distinguished from the ordinary attacks of vertigo 

 connected with cerebral disturbance. Their occurrence is 

 generally the occasion of directing attention to the examina- 

 tion of the pulse and heart's action, hitherto unattended to, 

 Avhen most probably both will be found abnormal, exhibiting 

 varying characters of inequality and irregularity of sequence. 



In cardiac diseases generally we have often indications of 

 the irregularity and insufficiency of the circulatory functions 

 by the persistent coldness of the extremities, and the appear- 

 ance of oedema, first of the limbs, and at length of the inferior 

 thoracic and abdominal regions, which, although continuous 

 and persistent from the time of its appearance, is often of 

 varying extent and severity. 



These general s3rmptoms of heart disease, either of its 

 membranes or more intimate structures, occur with different 

 degrees of frequency and severity, according to the charac- 

 ters of the affections and the structures more immediately 

 attacked. 



Cardiac diseases in the aggregate are usually regarded as 

 involving either the heart proper, or as confined to the true 

 cardiac membranes and their appendages. The diseases of 

 the heart itself may be — (a) Of the nature of functional dis- 

 turbance; or (h) The result of structural alteration. And 

 both disease of heart and membranes may be acute or 

 chronic. 



