HYPERTROPHY AND DILATATION OF THE HEART 89 



of alcohol, caffein citrate or ether subcutaneously. To reduce 

 the temperature acetanilid (dog 0.2-0.5; cat 0.05-0.1) should 

 be given twice daily. 



In endocarditis from rheumatic conditions, salicylic acid 

 or sodium salicylate (dog 0.2-0.5; cat 0.05-0.1) should be 

 administered twice daily. 



When general weakness is well marked, stimulants must 

 be administered according to the needs of the patient. 

 Camphor, ether, or atropin are best for this purpose. 



HYPERTROPHY AND DILATATION OF THE HEART. 



Definition.— Hypertrophy is an enlargement of the heart 

 due to a thickening of its musculature; dilatation is an 

 increase in the size of the heart from an enlargement of its 

 cavities. From a clinical standpoint a distinction between 

 them cannot be made as they nearly always coexist. Hyper- 

 trophy is an active enlargement of the heart, while dilatation 

 is a passive one. 



Etiology.— Generally speaking the causes of hypertrophy 

 of the heart are those conditions which interfere with the 

 circulation of the blood and thus increase the blood pressure. 

 The following are the most common: 



(a) Increased physical exertion. This occurs in dogs used 

 for hunting (fox hounds, greyhounds) . 



(6) Adhesions between the pericardium and heart inter- 

 fering with the heart action. 



(c) Obstruction to the free circulation through the arteries, 

 such as aneurysms of the aorta, stenosis of the aorta, thrombi, 

 atheromatous and arteriosclerotic processes, etc. 



(d) Defects in the valves of the heart (chronic endocar- 

 ditis) . 



(e) Diseases of the lungs, such as chronic interstitial 

 pneumonia (common in the dog), adhesions, exudations, 

 abscesses, chronic bronchitis, which increase the blood 

 pressure through the right heart. 



(/) Chronic inflammation of the liver, kidneys, etc., by 



impeding the free circulation of blood (common in old dogs) . 



(g) Dilatation of the heart usually follows hypertrophy, 



