466 Veterinary Medicine.. 



ness forming a most marked contrast to the violence of the heart's 

 impulse against the side. The irregularity and intermission of 

 the pulse is to be ascribed at first to the impaired nervous energy 

 of the heart, though later it is often due to the obstacle presented 

 by clots to the flow of blood from the heart, so that a beat some- 

 times takes place without a corresponding pulsation. It may 

 reach 80 or 160 per minute in horse or ox. Syncope sometimes 

 occurs. 



The blowing murmur when heard is one of the most character- 

 istic symptoms, but must be carefully distinguished from other 

 allied heart sounds. If very loud it may be confounded with the 

 friction sound of pericarditis, but may be differentiated by its 

 invariable coincidence with some particular portion of the heart's 

 beat. The absence of local tenderness is another distinctive 

 symptom. Again in pericarditis, effusion takes place early, an- 

 nuling friction sound, and diminishing alike the impulse and the 

 sounds of the heart. 



It is of less practical value to be able to distinguish the precise 

 seat of the murmur, yet the following data will guide to such a 

 conclusion. 



Simple induration or insufficiency of the Left Auriculo- 

 ventricular (Mitral) valve. Paroxysms of palpitation, op- 

 pression, and difficulty of breathing ; vertigo with loss of control 

 over the limbs and vacillating gait ; stupor, coma ; slight tremor 

 and blowing noise with the first sound of the heart ; heart's 

 impulse, violent, but irregular in force, sometimes double ; pulse 

 feeble, irregular, unequal or intermittent ; sometimes though not 

 at all constantly a venous pulse in the lower end of the jugulars. 

 In chronic induration of this valve, or in osseous or cartilagin- 

 ous degeneration, the same symptoms are shown. The more gen- 

 eral symptoms may, however, require exercise to develop them. 



Induration, etc., of the Right Auriculo-Ventricular (tri- 

 cuspid) valve. The symptoms are almost identical with the last. 

 Venous pulse is constant, and, particularly after exertion, the 

 veins generally are distended. Dropsies are more common. 



Narro-wing of the Mitral orifice. In addition to the same 

 general symptoms as the last named lesions, there is a sighing, 

 blowing, purring or rasping sound, according to the degree of 

 narrowing, heard before the first sound of the heart. It is the 



