Anatomical Changes, Symptoms. 1071 



extensive degeneration the muscle assumes an almost uniform 

 gray-yellow color. These changes are not alike in all sections 

 of the heart. Besides healthy or comparatively slightly changed 

 portions there are parts of the heart, of various extent, which 

 show very considerable disease. 



Metastasis or immediate continuation of a purulent in- 

 flammation from the vicinity leads to the formation of smaller 

 pus foci which form abscesses by gradual increase in size or 

 by confluence (Myocarditis purulenta). Injuries of the heart 

 muscle will also cause the formation of abscesses. The con- 

 tents of an abscess may eventually be inspissated into a cheesy 

 mass and even become calcified. It may also break into the 

 pericardial cavity or into a heart cavity. Occasionally ichorous 

 pus is found in the abscesses. (In the heart muscle of calves 

 which were apparently healthy Kitt found repeatedly a diffuse 

 necrosis which was similar to the necrosis observed in hogs 

 in the skeleton muscles.) 



Ssmaptoms. The functioning ability of the heart muscle 

 is diminished not only by the degeneration but also by the 

 inflammation in direct proportion to their intensity and ex- 

 tension. Consequently, the symptoms correspond with the 

 clinical picture of cardiac debility only if the affection is con- 

 siderable. The clinical picture of myocarditis occurring in 

 connection with acute infectious diseases develops as a rule 

 gradually. The number of heart beats increases three- or four- 

 fold. The heart beat is at first, and sometimes permanently, 

 increased and can be felt over a larger territory than usual 

 on account of the rapid contractions of the heart muscle which 

 is otherwise weakened. In contrast the pulse is feeble, some- 

 times thready and often arrhythmical. To these symptoms are 

 added signs of stasis, at first only in the form of a dark red 

 coloration or cyanosis of the visible mucous membranes while 

 at the same time the veins are filled more strongly. Later, 

 however, the larger veins are more prominent. All these symp- 

 toms may eventually retrogress slowly, the number of heart 

 beats becoming more and more normal, the pulse fuller and 

 its tension greater, while the blood stasis disappears, and with 

 the cure of the basic disease the cavity of the heart returns 

 to the normal. 



In severe cases, however, the disturbances increase, the 

 heart beat becomes more and more rapid, the pulse more 

 thread-like, irregular and intermittent, venous pulsation is 

 noticeable, the respiration is hastened and more or less labored. 

 Vertigo, trembling and debility become manifest, and finally 

 paralysis of the heart terminates the disease. In exceptional 

 cases the cardiac weakness develops so rapidly that the sick 

 animals fall down as though of an apoplectic stroke, and die 

 after a short time, for instance, in the malignant form of 

 foot and mouth disease, and sometimes also in influenza of 



