556 DISEASES OF THE PERICARDIUM. 



in appearance and consistence ; it is of a dark or dirty brown 

 colour, and when cut into is easily lacerated, seeming to want 

 cohesion, and having always, from the want of muscular power 

 and tenacity, a tendency to favour dilatation of the cardiac 

 cavities. T he white spots or patches Imown as ' milk-spots,' 

 so often seen on the surface of the heart, are usually ascribed 

 to diffuse and patchy pericarditis. Their intimate character 

 is not always similar, while their presence is so often observed 

 in hearts where the probabilities of the existence of a preyious 

 inflammatory action are very remote, that I am disposed to 

 regard them, if not always, at least in certain instances, as 

 owing their existence to rather different conditions. 



Symptoms. — The indications afforded us, either through the 

 occurrence of constitutional disturbance or peculiar local or 

 physical signs, of the existence of this diseased state of the 

 pericardium are exceedingly variable in their expression, while 

 it is doubtful if there are any of these which in the horse may 

 be entitled to be regarded as diagnostic. In certain instances, 

 when unassociated with general or constitutional disease, the 

 symptoms may be decidedly obscure, not at all indicative of 

 the involvement in disease of structures so essential to life 

 as the heart and its covering. When occurring associated 

 with such general diseases as rheumatism, influenza, and 

 extensive renal disturbance, the existence of inflammation 

 of the pericardium is sometimes indicated by symptoms not 

 easily mistaken. It is seldom, however, if we had merely to 

 depend upon either physical, local, or functional disturbance, 

 that we would be warranted in giving anything like a decided 

 opinion. 



The much depended upon to-and-fro friction- sound, and the 

 increased systolic bellows-murmur existing in the human 

 subject when suffering from pericarditis, are in the horse 

 rarely heard of such well-defined characters as to entitle us 

 to speak with confidence ; and Avhen detected, it is probably 

 owing to the fact that other concomitant circumstances have 

 led us to expect them, rather than from the nature of the 

 sounds themselves. 



When connected with the sthenic fever of simple rheu- 

 matism, or, indeed, when occurring at any time apart from the 

 adverse and preceding influence of some constitutional cachexia, 



