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exciting cause, the most alarming symptoms disappear in a week or ten 

 days, often leaving, however, such changes in the interior lining or 

 valvular structures as to cause impairment in the circulation for a much 

 longer period of time. These changes usually consist of thickening or 

 induration of the inflamed structures. But while the effects of the 

 inflammation in the membrane lining the walls of the ventricles may 

 subside to such a degree as to cause little or no inconvenience, or even 

 wholly disappear, yet after the valvular structures have been involved, 

 causing them to be thicker, less flexible than normal, they usually 

 remain, obstructing the free passage of the blood through the openings 

 of the heart, thereby inducing secondary changes which take place 

 slowly at first, but ultimately seriously impair the animal's usefulness. 

 What was but a slight obstruction to the circulation during the first 

 few weeks after the subsidence of the cardiac inflammatory attack 

 becomes in process of time so much increased as to induce increased 

 growth in the muscular structure of the heart, constituting hypertrophy 

 of the walls of the ventricles, more particularly of the left, with corre- 

 sponding fullness of the left auricle and pulmonary veins, thereby pro- 

 ducing fullness of the capillaries in the lungs, pressure ui)on the air 

 cells, difficult or asthmatic breathing — greatly increased in attempts to 

 work — until in a few months many of these cases become entirely dis- 

 abled for work. Sometimes, too, dropsical effusions in the limbs or into 

 the cavities of the body result from the irregular and deficient circula- 

 tion. Derangement of the urinary secretion, with passive congestion of 

 the kidneys, may akso appear. 



Endocardial inflammation is seldom fatal in its early stages, but in 

 many cases the recovery is incomplete, for a large proportion are left 

 with some permanent thickening of the valves, which constitute the be- 

 ginning of valvular disease. 



/Symptoms. — As already stated, myocarditis is seldom recognized until 

 p'ericarditis or endocarditis supervenes. Staggering gait with painful 

 ' movement of the forc-lirabs, a constant irregularity of the heart's action, 

 but equality of strength regardless of the rapidity of the heart-beats, 

 constitute perhaps the most prominent symptoms which characterize 

 myocarditis. When the disease is associated with rheumatism, influ- 

 enza, or other zymotic diseases, these symptoms may not be sufficiently 

 well defined to attract the attention they deserve, and medical treat- 

 ment prescribed for the mitigation of such disease often serves to ag- 

 gravate the cardiac affection. In chronic myocarditis we generally 

 find a persistent palpitation with irregularity of beat, which, upon ex- 

 ercise, becomes greatly intensified. Change in the sounds of the heart 

 do not occur unless pericarditis, endocarditis, or disease of the valves 

 are associated with myocarditis. When it leads to hypertrophy we may 

 find an abnormally increased area of dullness on percussion. In endo- 

 carditis, when the attack is sudden and severe, we may find many of the 

 symptoms which characterize pericarditis and pleuritis, but a close ex- 

 amination will reveal notable differences. 



