USCULAR STRUCTURE OF THE HEART.

The heart muscle sometimes becomes inflamed as a complication or result
of the existence of general or febrile and of infectious diseases.
Severe influenza or infectious pneumonia is not infrequently followed by
myocarditis. By extension of inflammation of the endocardium or
pericardium the muscle of the heart may become involved. Overexertion or
especially hard work continued for a long time may cause this muscle to
become inflamed.

_Symptoms._--Inflammation of the heart muscle is shown by inability to
contract forcibly. This results in a rapid but weak, soft pulse and
irregular heart sounds. The pulse may be quite irregular as a result of
the irregular, tumultuous action of the heart. There is great general
weakness, shortness of breath, and rapid respiratory movements. In some
cases, where the muscle is very much softened and weakened, or, perhaps
when an abscess forms in the wall of the heart, the course of the
disease is very rapid and terminates suddenly from paralysis or rupture
of the heart.

_Alterations._--The heart muscle has a brownish or yellowish, boiled
appearance, and is so brittle that it tears easily. There may be a
spotted appearance of the muscle from the intense changes in structure
in small areas. These small areas may be due to suppuration, in which
case they have the characteristics of small abscesses. This last
condition is seen in pyemia (blood poisoning). If the disease is of long
duration, the fibrous tissue in the wall of the heart may increase to
such an extent as to produce an unnatural hardness of the wall.

_Treatment._--In this disease the nutrition and strength of the heart
should be kept up as much as possible with good food, good care, and
heart tonics and stimulants. The horse should be tempted to eat such
foods as he will take; he should be kept in an airy box stall; his legs
should be well rubbed as often as necessary to keep them warm and
bandaged loosely with flannel bandages. Internally the horse may have
strychnia, in 2-grain doses twice daily, whisky in 4-ounce doses every
two to four hours, digitalis in the form of the tincture in doses of 1
dram every three to six hours. Artificial Carlsbad salts in heaping
tablespoonful doses in the feed may be given three times daily for a
couple of weeks. Rest is of the greatest importance and should be
allowed for a few weeks after recovery seems to be complete.

ENDOCARDITIS, OR INFLAMMATION OF