ENDOC/IRDITIS 81 



ditis may be distinguished: (a) Acute parenchymatous, 

 (6) chronic interstitial, and (c) piu-ulent (heart abscess). 



(a) The acute parenchymatous form involves the muscle 

 fibers of the heart. Macroscopically the heart appears often 

 striped or spotted (tiger heart), is of friable consistency 

 and lighter color than normal. 



(6) The chronic interstitial myocarditis involves the inter- 

 muscular connective tissue which proliferates, leading in many 

 cases to a thinning from atrophy of the heart muscle with 

 occasional local distention of the cavities (heart aneurysm.) 



(c) Abscess of the heart is usually seen in traumatic 

 myocarditis of cattle and in pyemia. The musculature 

 of the heart will contain a number of pea- to walnut-sized 

 abscesses, or in some cases small, multiple, miliary pus 

 centers. 



Symptoms. — ^Acute myocarditis begins suddenly with 

 symptoms of heart weakness (palpitation, very rapid pulse, 

 dyspnea). Death may be apoplectic due to heart paralysis. 

 Clinically it is extremely difficult to distinguish between 

 myocarditis and acute dilatation of the heart, or the paren- 

 chymatous degenerations so common in febrile disorders. 

 Dicing life myocarditis is usually not diagnosable in animals. 

 From pericarditis and endocarditis it may be distinguished 

 by the absence of the characteristic bruits of these conditions. 



Treatment. — ^Heart stimulants especially injections of oil of 

 camphor (Biij), or caffein (3j), or veratrin are recommended. 



ENDOCARDITIS. 



Definition. — ^An inflammation of the endocardium which 

 may be (a) acute or (6) chronic. 



Acute Endocarditis. — ^Acute endocarditis is usually of 

 infectious or hematogenous origin. It may therefore be 

 due to several different microorganisms. In animals it is 

 usually caused by the bacteria of septicemia and pyemia. 

 The streptococci, staphylococci, and varieties of the colon 

 bacillus, which have entered the blood in puerperal septicemia 

 and pyemia of the ox or wound infection in the horse, are 

 common causes. 

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