PERICARDITIS. 



457 



tismal nature and results from colds, as frequently happens in 

 the horse; it may also be developed in the course of infectious 

 diseases, muscular or acute articular rheumatism, septicemia, con- 

 tagious pneumonia of the horse, and simple pneumonia. It is 

 sometimes the consequence of the propagation upon the pericar- 

 dium of an inflammation from a neighboring organ (endocarditis, 

 pleurisy, myocarditis, pneumonia) ; it sometimes accompanies an 

 empyema developed as a consequence of the opening of a pulmo- 

 nary abscess in the pleura — here it always starts on the external 

 fold of the pericardium. It may also appear in the course of 

 chronic nephritis. According to Anacker, sheep are subject to an 

 enzootic pericarditis, which is usually fatal within a few days. 



In very rare cases it is of a traumatic nature. In a horse, Hen- 

 niges has found, in the right auricle, a sewing-needle which had 

 reached this place through the œsophagus. Finally, it may occur 

 consecutively to fractures of the ribs, to the penetration of shot into 

 the pericardium (dog), etc. 



Patholog'ical anatomy. At the beginning we observe conges- 

 tion, ecchymosis, and a turbid tumefaction of the serous membrane, 

 which is covered by a gelatinous exudate, spread in a thin layer 

 and easy to detach. According to the nature of the affection, we 

 find in the pericardium a serous or fibrinous exudate (cold), hemor- 

 rhagic, purulent, putrid (septic infection), the quantity of which is 

 very variable. In the dog and the sheep pericarditis generally 

 takes a chronic type; its lesions are those of hydro-pericarditis. 

 At a more advanced period the epicardium becomes covered with 

 rugous lardaceous neoformations (cor villosum), and the heart forms 

 adhesions with the pericardium (cardiac symphysis) ; it is hyper- 

 trophied or atrophied. In the horse, Prakke has found it reduced 

 to the size of a child's fist ; in some places its walls were only as 

 thick as a playing-card. The other alterations are similar to those 

 of pericarditis of the ox. 



Symptoms. In the beginning the impulse of the heart is palpi- 

 tating, tumultuous ; later, in proportion to the increase of the quan- 

 tity of exudate, it gradually weakens; the precordial dulness is 

 extended upward and backward ; we observe bruits of friction; the 

 pulse is accelerated, small, irregular, unequal ; the respiration is 

 dyspnœic ; we observe a venous pulse, the temperature varies from 

 39° to 40.5°, etc. In the horse, in one case, Bruckmiiller only 

 observed fever, the obliteration of the precordial impulse and diffi- 



