260 DISEASES OF THE HORSE. 



the absence of stertorous breathing and lividity of the visible mu- 

 cous membranes. 



Treatment. — Dash cold water on the head ; administer a stimu- 

 lant — 4 ounces of whisky or half an ounce of carbonate of ammonia. 

 Prevent the animal from getting up too soon, or the attack may 

 immediately recur. Afterwards, if the attack was due to weakness 

 from loss of blood, impoverished blood, or associated with debility, 

 general tonics, rest, and nourishing food are indicated. 



HYPERTROPHY OF THE HEART, OR CARDIAC ENLARGEMENT. 



Hypertrophy of the heart implies augmentation of bulk in its 

 muscular substance, with or without dilatation or contraction of its 

 cavities. It may exist with or without other cardiac affections. In 

 valvular disease or vah'ular insufficiency hypertrophy frequently re- 

 sults as a consequence of increased demand for propelling power. 

 The difficulties with which it is most frequently connected are dilata- 

 tion and ossification of the valves. It may also occur in connection 

 with atrophied kidneys, weak heart, etc. It may be caused by an 

 increased determination of blood to the organ or from a latent form 

 of myocarditis, and it may arise from a long-continued increase of 

 action dependent upon nervous disease. All the cavities of the heart 

 may have their walls hypertrophied or the thickening may involve 

 one or more. AVhile the wall of a ventricle is thickened, its cavity 

 may retain its normal size (simple hypertrophy) or be dilated (eccen- 

 tric hypertrophy), or it may be contracted (concentric hypertrophy). 

 Hypertrophy of both ventricles increases the length and breadth of 

 the heart. Hypertrophy of the left ventricle alone increases its 

 length; of the right ventricle {Jone increases its breadth toward the 

 right side. Hj^pertrophy with dilatation may affect the chambers 

 of the heart conjointly or separately. This form is by far the most 

 frequent variety 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. 



Symptoms. — In hypertrophy of the heart, in addition to the usual 

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

 erful 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 give rise to local inflamma- 

 tion, active hemorrhage, etc. 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 hypertrophy. In case of hypertrophy with dilatation, the im- 

 pulse is not only powerful and heaving, but it is diffused over the 



