PREVENTION, SYMPTOMS AND TREATMENT lQ y 



fails, symptoms appear and medical care becomes imperative. Valv- 

 ular disease is common to all animals, particularly so to the horse, 

 dog and pig. Acute endocarditis, secondary to the various infec- 

 tions, is often the beginning of the chronic form, but over-exertion,, 

 atheroma, etc., are also etiological factors. 



Symptoms. — These indicate loss of compensation (dilatation) 

 and consists in dyspnea and weakness on exertion, palpitation with 

 rapid (rarely slow) and often irregular pulse, cyanosis, dropsy and 

 edema, and valvular murmurs. The murmurs are systolic in time 

 in stenosis, and diastolic in incompetency of the various valves. 

 The auriculo-ventricular valves are those most often affected. The 

 occurrence of a valvular murmur does not, however, indicate or- 

 ganic valvular defect, as murmurs are heard in anemia, during ex- 

 hausting disease, etc. (relative incompetency). In such cases the 

 general symptoms following loss of compensation are absent. The 

 use of the stethoscope (see Acute Endocarditis) will greatly facili- 

 tate diagnosis. 



(b) Enlargement of the Heart, Hypertrophy and Dil- 

 atation. — Under this head we consider simple hypertrophy, a heart 

 with thickened walls; hypertrophy with dilatation, a heart with 

 thickened walls and dilated cavities (the common form) ; and 

 simple dilatation, a heart with large cavities and thinning of the 

 walls. The symptoms and treatment differ considerably according 

 to the pathology. The etiology embraces valvular disease, over- 

 exertion, myocarditis, pericardial adhesions, plethora and obstruc- 

 tions in the circulation, especially lung disease, and arteriosclerosis. 

 The disease is more often seen in horses and old dogs. 



In simple hypertrophy there may be no symptoms and a regular, 

 full, strong pulse with enlargement of the cardiac area of dulness. 

 Or palpitation may occur with a loud, strong, prolonged first 

 sound and strong, clear second cardiac sound. With dilatation and 

 hypertrophy the impulse of the heart is forcible and abrupt. As. 

 hypertrophy fails and dilatation ensues the pulse becomes irregular 



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