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 valvular 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. While 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 alone increases its breadth toward the 
right side. Hypertrophy 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.—tin hypertrophy of the heart, in addition to the usual 
symptoms manifested in organic diseases of the heart, there isa 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 lccal 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 cnly powerful and heaving, but it is diffused over the 
