350 DISEASES OF THE HEAET. 



it is usually connected with dilatation of the right auricle, or 

 insufficiency of the mitral valve. 



Vertigo is another symptom indicating a more severe form 

 of organic lesion. A horse is for some time known to be 

 unsound, or rather very incapable for any severe exertion. 

 He is suddenly seized with symptoms of megrims when 

 being driven, and on careful examination no pressure on the 

 veins of the neck by the collar is found to have produced 

 such an effect. The attacks recur, and the animal has to be 

 thrown off work. He suddenly reels to and fro in the 

 stable, and falls back or sinks to the ground as if shot, 

 recovering himself when in the recumbent posture, and 

 becomes unfit for work of any kind. Such a form of 

 staggers is invariably due to interference with the heart's 

 action by organic disease. It must not be confounded with 

 coma or sleepy staggers, nor with stomach staggers, or ordi- 

 nary attacks of megrims. 



Irregularity and frequency of the pulse is another of the 

 general symptoms, which, though observed in fevers, &c., is 

 commonly the first characteristic sign which leads to a local 

 examination of the heart. 



Habitual coldness of the ears and extremities, indicating a 

 languid circulation, is a very useful sign. 



QEdema first occurring in the hind legs, then in the fore, 

 and lastly in the chest and belly, is a useful symptom charac- 

 teristic in some heart affections. 



However active and nervous an animal may naturally be, 

 if seized with cardiac disease, a change occurs, and there is a 

 tendency to obesity, dulness, inactivity, and, in the majority 

 of instances, a chance of some sudden and irremediable inter- 

 ference with the propulsion of blood, hence instantaneous 

 death. 



Indeed it were well if the pulse was more frequently felt 



