AORTIC INSUFFICIENCY IN THE HORSE. I3I 



on which I have laid stress — the diastolic murmur and the bounding 

 pulse — are absolutely characteristic. In certain cases, when the 

 heart's impulse is weak and the murmur very loud, it may be regarded 

 as systolic. I have often corrected this error. In order to avoid it one 

 need only trot the animal for a few moments. The impulse of the 

 heart becomes very marked, and no doubt can exist of the diastolic 

 character of the murmur. The most useful indications may, however, 

 be wanting. Some animals with valvular lesions and insufficiency 

 continue work as usual without showing dyspnoea or weakness ; it is 

 not until later that functional troubles attract attention. Aortic 

 insufficiency cannot well be mistaken for any other disease of the heart. 

 In the horse insufficiency of the pulmonary sigmoid valves is extremely 

 rare, and the pulse (which is sometimes small) differs entirely from that 

 of aortic insufficiency. 



The prognosis is grave, not only because the condition causes 

 immediate danger and may produce death in a very short time, but 

 because it generally interferes to a large extent with the animal's use- 

 fulness. As a rule animals suffering from it pass successively into the 

 hands of poorer and poorer owners, who expect more and more work. 



Some lose condition rapidly, others retain it for a considerable 

 time. In all, the normal vigour and working powers steadily diminish ; 

 when the patients become incapable of further work they are usually 

 slaughtered. Most of them, however, are sold and resold several times 

 before death. This is evident from animals being brought here at 

 intervals of a few weeks after having changed hands. In 1890 one was 

 thus brought on three separate occasions during a single month. A 

 little later we saw it again — this time amongst the animals purchased 

 for surgical exercises. 



Like all other chronic valvular changes, those of the aortic semi- 

 lunar valves producing aortic insufficiency are incurable. Treatment 

 is purely palliative. The principal drugs employed are the iodides of 

 potassium and sodium, given for periods of two to three weeks ; and 

 when signs of cardiac failure appear, digitalis and diuretics. 



