238 BUREAU OF ANIMAL INDUSTRY. 



{sinqyle hypertrophy) or be dilated {eccentric hypeiirophy) or it ma}' be 

 contracted {co7iccntric hypertrophy). H^pcrtroph}- of both ventricles 

 increases the length and breadth of the heart. Hypertropliy of the 

 left ventricle alone increases its length, of the right ventricle alone 

 increases its })readth toward the right side. HA'pertrophy with dilata- 

 tion may affect the chambers of the heart conjointh' or separately. 

 This form is by far the most frequent Aarietv of cardiac enlargement. 

 When the entire heart is affected it assumes a globular appearance, the 

 apex being almost obliterated and situated transversely in the chest. 

 The bulk may become three or four times greater than the average 

 heart. 



S'ymptoras. — In hypertrophy of the heart, in addition to the usual 

 symptoms manifested in organic diseases of the heart, there is a power- 

 ful and heaving impulse at each beat, which may be felt on the left 

 side, often also on the right. These pulsations are regular, and when 

 full and strong at the jaw there is a tendency to active congestion of 

 the capillary vessels, which frequently gives rise to local inflammation, 

 active hemorrhage, ej:c. If the pulse is small and feeble at the jaw we 

 may conclude that there is some obstacle to the escape of the blood from 

 the left ventricle into the aorta, which has given rise to the hj'pertro- 

 phy. In case of hypertrophy with dilatation, the impulse is not only 

 powerful and healing, but it is diffused over the whole region of the 

 heart, and the normal sounds of the heart are greatly increased in 

 intensity. Percussion reveals an enlarged area of dullness, while the 

 impulse is usualh' much stronger than normal. 



Drops}' of the pericardium will give the same wide space of dullness, 

 l)ut the impulse and sound are lessened. An animal with a moderate 

 degree of enlargement may possibly live a number of years and be 

 capable of ordinary work; it depends largely upon concomitant disease. 

 As a rule, an animal affected with hypertrophy of the heart will soon 

 be incapacitated for work, and it becomes useless and incurable. 



Treatment. — If the cause can be discovered and is removable, it should 

 be done. The iodide of potassa, in cases of valvular thickening, ma}- 

 be of some benefit if continued for a sufficient length of time; it may be 

 given in 2-dram doses, twice a day, for a month or more. The tincture 

 of digitalis ma}' be given, in cases where the pulse is weak, in doses of 

 2 teaspoonf uls three times daily. This remedy should not be continued 

 if the pulse becomes irregular. General tonics, freedom from excite- 

 ment or fatigue, avoidance of bulky food, good ventilation, etc., are 

 indicated. 



DILATATION OF THE HEART. 



This is an enlargement, or stretching, of the cavities of the heart, 

 and may be confined to one or extend to all. Two forms of dilatation 

 may be mentioned — mm2>le dilatation, where there is normal thickness 



