GENERAL THERAPEUTICS OF THE DISEASES OF THE 

 ORGANS OF CIRCULATION 



I. General Therapeutics of the Diseases of the Heart 



Pathology. — Therapeutically, the most important heart dis- 

 eases of the domestic animals are chronic endocarditis (valvular 

 insufficiency) and cardiac dilatation (heart weakness) of horses, 

 cattle and dogs. On the other hand, the most frequent heart dis- 

 ease of cattle, traumatic pericarditis, due to the passage of metallic 

 foreign bodies from the reticulum through the diaphragm to the 

 pericardium and heart, is practically not affected by therapeutic 

 measures. Chronic endocarditis leads to valvular insufficiency, 

 with secondary compensatory hypertrophy, and later to cardiac 

 dilatation. In the horse and dog there is usually an insufficiency of 

 the mitral valve; in cattle, more frequently an insufficiency or 

 stenosis of the tricuspid. Acute cardiac dilatation and cardiac 

 degeneration occurs frequently in all the domestic animals, but 

 especially in the horse and dog. It is manifested by cardiac weak- 

 ness and is usually associated with infectious diseases: contagious 

 pneumonia, foot-and-mouth disease, septicsemia; sometimes with 

 overexertion (horses). Fatty degeneration of the heart is fre- 

 quently observed in dogs and swine. 



Physiology. — ^The action of the heart consists of a rhythmical 

 contraction and relaxation of the cardiac muscle (systole, diastole, 

 pause). During systole the blood is under positive pressure; dur- 

 ing diastole it is under a negative pressure, corresponding to the 

 sucking of a pump. The pause, or period of rest, is especially 

 important because it affords opportunity for the recuperation of 

 the heart. The valves serve to regulate the flow of blood. The 

 cardiac muscle is innervated by the vagus, the inhibitory nerve, and 

 by the sympathetic, which is the accelerator nerve; in addition, 

 there are also automatic intracardial centres. The heart muscle 

 and the nerves as well can be therapeutically stimulated by me- 

 chanical, chemical, thermic and electrical stimuli. On the other 

 56 



