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 impulse is not
only powerful and heaving, 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 usually much stronger than normal.

Dropsy of the pericardium will give the same wide space of dullness, but
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 becomes useless and incurable.

_Treatment._--If the cause can be discovered and is removable, it should
be done. The iodid of potassium, in cases of valvular thickening, may 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 may be given, in cases where the pulse is weak, in doses of 2
teaspoonfuls three times daily. This remedy should not be continued if
the pulse becomes irregular. General tonics, freedom from excitement 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--simple dilatation, where there is normal thickness of the
walls, and passive, or attenuated, dilatation, where the walls are
simply distended or stretched out without any addition of substance.

_Causes._--Any cause producing constant and excessive exertion of the
heart may lead to dilatation. Valvular disease is the most frequent
cause. General anemia predisposes to it by producing relaxation of
muscular fiber. Changes in the muscular tissue of the heart walls,
serous infiltration from pericarditis, myocarditis, fatty degeneration
and infiltration, and atrophy of the muscular fibers may all lead to
dilatation.

_Symptoms._--The movements of the heart are feeble and prolonged, a
disposition to staggering or vertigo, dropsy of the limbs, very pale or
very dark-colored membranes, and difficult breathing on the slightest
excitement.

_Treatment._--Gene