233 



the sounds of the heart does not occur unless x)ericarditis, endocarditis, 

 or disease of the valves is associated with myocarditis. When it 

 leads to hypertroj)hy we may find an abnormally increased area of 

 dullness on j)ercussion. In endocarditis, when the attack is sudden 

 and severe, we may find many of the symptoms which characterize 

 pericarditis and pleuritis, but a close examination will reveal notable 

 differences. 



Endocarditis may be ushered in by a chill, with sudden and marked 

 rise in temperature. The pulse rapidly decreases in strength or may 

 become irregular, while the heart beats more or less tumultuously. In 

 the early stages soft blowing sounds may be heard Ijy placing the ear 

 over the heart on the left side, which correspond in number and 

 rhythm to the heart's action. Excessive pain, though not so great as in 

 acute pleuritis, is manifested when the animal is compelled to trot; 

 very often difficulty in breathing — shortness of breath — on the slight- 

 est exertion develops early in the attack. AVhen the valves are 

 involved in the inflammatory j)rocess the visible mucous membranes 

 become either very pale or verj^ dark colored, and fainting may occur 

 when the head is suddenly elevated. When the valves of the right 

 side are affected we may have a regurgitant pulsation in the jugular 

 vein. In some cases we find marked lameness of the left shoulder, 

 and when the animal is turned short to the left side he may groan with 

 pain, and the heart's action become violently excited, although pres- 

 sure against the chest-wall will not produce pain unless roughly 

 applied. The animal is not disposed to eat or drink much; the sur- 

 face of the body and legs are cold — rarely excessively hot — and fre- 

 quently the body of the animal is in a subdued tremor. In nearly all 

 cases there is i)artial suj^pression of the urinary secretion. The S3'mp- 

 toms may continue with verj^ little modification for three or four daj's, 

 sometimes seven days, without any marked changes. If fibrinous 

 clots form in the heart the change will be sudden and quickly prove 

 fatal unless iliey become loosened and are carried awaj^ in the circu- 

 lation; then apoplexy may result from the plugging of arteries too 

 small to give further transmission. If the animal manifests symp- 

 toms of improvement, the changes usually are slow and steady until 

 he feels apparentlj^ as well as ever, eats well, and moves freely in his 

 stall or 5'ard. When ho is taken out, however, the seeming strength 

 often proves deceptive, as he may quickly weaken if urged into a fast 

 gait, the breathing become quickened with a double flank movement 

 as in heaves, and all the former symjitoms reappear in a modified 

 degree. An examination at this stage may reveal valvular insufiici- 

 enc}', cardiac hypertrophy, or pulmonary engorgement. 



In fatal cases of endocarditis death often occurs about the fourth 

 day, from the formation of heart clot or too great embarrassment of 

 the circulation. Endocarditis may be suspected in all cases where 

 59G1— HOR 8* 



