186 MANUAL OF EQUINE MEDICINE. 



Cyanosis is a condition very rarely met with. It only 

 affects very young animals, and they only live a very short 

 time. It is due to patency of the foramen ovale, and con- 

 sequent mingling of arterial and serous blood. 



It is manifested by blueness of the visible mucous mem- 

 branes, difficulty of breathing, and coldness of the surface. 



ACUTE AFFECTIONS OF THE HEART. 

 ACUTE ENDOCARDITIS. 



Definition. — Is inflammation of the endocardium linins; 

 the cavities and valves of the heart. 



Etiology. — Acute endocarditis in horses is usually asso- 

 ciated with pericarditis, and endo-pericarditis is the most 

 frequently met of all acute diseases of the heart. It is 

 especially observed in rheumatism, several specific fevers, in 

 pyasmia, and many forms of septic poisoning. 



Acute endocarditis as a primary affection is probably 

 very rare in the horse. Mr. C. Gresswell, of Nottingham, 

 has, however, had sevei-al cases of this disease in young 

 thoroughbred foals. 



Symptoms. — Inflammation of the endocardium is in 

 most instances attended with pyrexia, increased frequency 

 of the pulse, and dyspnoea. When it follows in the course 

 of rheumatic inflammation there is exacerbation of the 

 febrile manifestations and obvious cardiac disturbance. 



The heart's action is tumultuous, and apparently forcible, 

 but the pulse is feeble. In listening to the chest we may 

 hear pericardial friction, if the outer serous membrane is 

 inflamed, and cooing murmurs, though sometimes audible 

 in endocardial inflammation, are so frequently disguised by 

 other abnormal sounds, as not to be relied upon in forming 

 our diagnosis. 



