OF VETERINARY MEDICINE. 199 



with which it is often associated) and terminates in the same 

 way with serous efifusion into the pericardium, constituting hy- 

 dropericardium, the same as hydrothorax. 



Etiology. — Pericarditis may be induced by cold, damp stabUng. 

 exposure and fatigue, wounds caused by broken ribs and blood 

 contamination. Diseases that usually exist as complications are 

 influenza, strangles, purpura hemorrhagica, pyaemia, rheumatism 

 and probably most common of all is rheumatic fever. These 

 diseases may cause the inflammation of the pericardium through 

 the blood, but the inflammation can also extend to the heart sac by 

 the inflamed adjacent tissues. 



Semciology. — Wlien arising as it usually does from some 



previously existing fever, the symptoms of the original disease 



will be the most prominent. As the pericarditis develops you 



will notice that the heart gets weaker and becomes irregular in 



rhythm and strength ; the heart then becomes so weak as to bring 



on distressing dyspnoea, such as seen in influenza and rheumatic 



fever. If the inflammation is not severe the effusion that follows 



will be small. The various stages will be like those of pleurisy. — 



first, congestion; second, inflammation; third, effusion. In case 



of extensive effusion the fluid often coagulates and coats the 



heart and the inside of the pericardium, the layer may be a 



half inch thick. This causes the muscles of the heart to soften 



and w^eaken. The pulse gets weak, soft and fluttering and there 



is always considerable fever usually about 104' F. This condition 



tends to dyspnoea and consequently a watery effusion increases 



in the sack. The dyspnoea is due entirely to the faulty thoracic 



circulation. In consequence of the altered circulation and passive 



congestion there is more or less exudation and the lungs become 



sufficiently involved to get a cough associated wnth the disease. 



With the increased weakness of the heart there \\\\\ be coldness 



of the extremities, oedematous enlargements, loss of strength, 



finally collapse and death. Even where the trouble is moderately 



severe it usually leaves a chronic lesion and affects the horse 



afterw^ard. Ante mortem clots may form in the posterior aorta 



and cause sudden death. 



Treatment. — If the condition can be diagnosed in the first 

 stage depletion is indicated. You can give diuretics and quinine. 



