452 VEGETABLE DRUGS 



to strengthen the heart and obviate passive pulmonary con- 

 gestion and cough. Valvular disease of the heart, in its 

 various phases, is the most common field of usefulness for 

 digitalis in human medicine, but in veterinary practice these 

 disorders are rarer and the exact lesion difficult or impos- 

 sible to diagnose. In mitral stenosis and regurgitation and 

 aortic stenosis, with lack of compensatory hypertrophy of 

 the heart and evidence of circulatory disturbances, digitalis 

 is clearly indicated. In these conditions the drug enables 

 the heart to pump more blood into the arteries and prevents 

 engorgement of the right heart and veins and the occurrence 

 of dropsy. Digitalis is counter-indicated in aortic insuffi- 

 ciency, because in prolonging diastole it allows more time 

 for the blood to flovv back from the aorta through the leaky 

 valve into the ventricle. As a general proposition, digitalis 

 is inferior to aconite in simple cardiac hypertrophy. But 

 this does not apply when enlargement of the heart is insuffi- 

 cient to compensate for -valvular lesions. 



Digitalis is extremely successful in palpitation of the 

 heart (horses) following over-exertion, but is not appropriate 

 in palpitation due to nervousness (dogs), or to indigestion. 

 Digitalis may be exhibited to advantage in rheumatic fever 

 and in endocarditis or pericarditis to quiet the heart and 

 secure rest by prolonging diastole. 



2. Digitalis is a valuable diuretic in dropsy of cardiac 

 prigin by stimulating the heart and overcoming venous stasis 

 in the kidneys and elsewhere.* It is often 'desirable to com- 

 bine iron preparations with digitalis. Turbidity results 

 from the action of iron on the tannic acid contained in digi- 

 talis when in solution, but this can be removed by the 

 addition of a little diluted phosphoric acid. 



3. Since digitalis contracts the uterus and blood vessels, 

 it has been prescribed in uterine haemorrhage, and to stop 

 bleeding from other internal parts ; but it is inferior to ergot 

 on account of the general rise of blood tension. Haemoptysis, 

 due to passive congestion of the lungs in mitral disease, is 

 relieved by digitalis. 



* It is often combined for this purpose with calomel, squill, juniper, potas- 

 sium acetate and nitre. See Dropsy, section on treatnrent. 



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