448 DISEASES OF THE CIRCULATORY SYSTEM. 



pulse is not at all in proportion with the violence of the impulse 

 of the heart; as a rale, it is weak, almost inappreciable; under the 

 influence of moderate exertions it acquires an extraordinary fre- 

 quency, and becomes irregular and unequal ; we observe very often 

 a venous pulse. At rest the respiration is already considerably 

 accelerated ; work makes it dyspnoeic (cardiac asthma, weak heart) ; 

 it may become asphyxiating : the animals stagger, fall, and perish 

 from apoplexy. In some cases we observée vertiginous attacks, 

 tremblings, convulsious, and sweating-spells. 



The circulatory troubles which occur afterward sometimes affect 

 the encephalon (congestion or cerebral anemia, marked by vertigo 

 and syncopal phenomena), at times the bronchial mucous membrane 

 (bronchitis), the digestive canal (chronic intestinal catarrh), the 

 liver (hepatic stage, cardiac liver), the kidneys (renal infiltration, 

 albuminuria, and oliguria), etc. Finally, we note the appearance 

 of cyanosis and dropsies (ascites, hydro-pericardium, hydrothorax, 

 anasarca). The sternal and lower abdominal regions, and the legs 

 become oedematous. Sometimes the animals become emaciated and 

 die of marasmus, at other times they are carried away by a con- 

 secutive pulmonary embolism due to the coagulation of the blood 

 in the heart; finally, at times death is the result of cardiac paralysis, 

 of cerebral hemorrhage, or of carbonic intoxication. 



The symptoms which have just been explained are most fre- 

 quently remarked in old dogs, appearing in an alarming dyspnœa 

 or in attacks of vertigo; they are also observed upon broken- 

 winded horses, but they are rare in subjects of our other domestic 

 species, Herran has recognized cardiac hypertrophy in an ox 

 which wasted away and showed symptoms of dyspnœa ; when this 

 animal was obliged to make any exertions he would stop abruptly 

 on account of the tumultuous beatings of the heart. 



Differential diagnosis. In the majority of cases hypertrophy 

 and dilatation of the heart are taken for a primary pulmonary dis- 

 ease — pulmonary congestion or pneumonia — because dyspnœa is 

 the predominant manifestation of it, and that which always attracts 

 the attention of the owner. Auscultation and percussion of the 

 lung, the progressive evolution and long duration of the disease, 

 lastly the phenomena observed w^ith reference to the heart, enable 

 us to make the diagnosis. 



Cardiac palpitations are distinguished from hpertrophy by the 

 intermittence of their manifestation, by the want of augmentation 



