RESPIRATORY APPARATUS. 



91 



timately related to either systole or diastole. Pericardial bruits, 

 when present, muffle the regular heart sounds. 



A pericardial metallic gurgling or liquid bruit, synchron- 

 ous with the heart's beat, occurs in the course of traumatic 

 pericarditis when fluid exudate and gas commingle in the peri- 

 cardium. 



Diseases of the Circulatory Apparatus. 



Palpitation of the heart (palpitatio cordis) is a nervous, transient, 

 greatly increased heart's action not due to any anatomical lesion in 

 the organ. The loud thumping of the heart may shake the thorax and 

 be heard a distance from the bodv. 



Acute myocarditis. A diffuse parenchymatous affection of the 

 heart's muscle which attends severe infectious diseases. Symp- 

 toms: great weakness and debility, mucous membranes cyanotic, 

 high fever, heart's beat weak, systolic sound muffled. Pulse very 

 rapid up to 120 in the horse; small, weak arhythmic, inequal, finally 

 impel ceptible. Course acute or peracute. Mortality high. 



Hypertrophy and dilatation of the heart. Can be present for 

 years without visible symptoms occurring. Symptoms: Pulse 

 strong, also heart impulse, zone of cardiac dullness enlarged on 

 percussion. Later when the heart is greatly dilated and the valves 

 can no longer close sufficiently, symptoms of bicuspid insufficiency 

 occur; pulse rapid, arhythmic, inequal; heart's beat sometimes 

 palpitating, increased dullness on percussion. Systolic blowing 

 bruit, diastolic sound intact or louder than normal. Exercise causes 

 dyspnea from pulmonary venous congestion. Termination a'? in 

 chronic valvular disease. Most common heart disease of horse 

 and dog. 



Acute endocarditis. Not very common. Fever, greatly ac- 

 celerated heart's action, irregular pulse, intermittent, very small. 

 Heart sounds are at first normal, later systolic bruit. Dyspnea. 

 General condition altered. Prognosis unfavorable. 



Valvular disease, chronic endocarditis. Caused by a chronic 

 valvular endocarditis which leads to an atrophy of the valves 

 (insufficiency) or to a narrowing of the orifices (stenosis). Fol- 

 lowing valvular failure a hypertrophy of the ventricle always takes 

 place; in disease of the semilunar valves the left ventricle,_ in 

 defects of the mitral valve a hypertrophy of the right ventricle. 

 The hypertrophy of the ventricle, which is combined with dila- 

 tation, is compensatory. 



Bicuspid (Mitral) insufficiency. Most common ferm 

 of heart disease in dogs and horses. Pulse small, irregular. Sys- 



