VARIOUS CARDIAC INFLAMMATIONS. I4I 



various divisions or compartments, valves, outlets and inlets, and 

 the ocular demonstration will no doubt render it easier to distin- 

 guish between the different parts already frequently referred to 

 and to be alluded to hereafter. By carditis is meant inflammation 

 of the substance of the muscular walls; it is derived from the 

 Latin word cardis, which means heart; endocarditis is a term 

 which implies inflammation of the endocardium (or internal lining 

 membrane) of the organ; it consists of a very fine, glazed, fibrous 

 membrane, which with care may be peeled off the muscular walls. 

 Valvulitis indicates that the inflammation has attacked the fine 

 membrane which extends ov-er and covers the valves. By some 

 authorities on equine medicine, notably the late Professor Robert- 

 son, it is considered that the horse is rarel}^ the subject of these 

 inflammations as independent diseases; whether this is absolutely 

 the case we are not prepared to say, but that they do occur, and 

 that not infrequently, we are satisfied; and whether arising inde- 

 pendently or in association with some other morbid condition, they 

 are sufficiently pronounced to demand our careful attention; more- 

 over, if the totality of the symptoms serv'es as a guide in the selec- 

 tion of a drug, both those of the heart and the associated disease, 

 if there be any, will 3 ield to the action of such drug; hence there 

 is no necessity to be so careful in distinguishing between inde- 

 pendent and associated disease. Horses are frequently the sub- 

 jects of rheumatism, and as there would appear to be some inti- 

 mate relation between that disease and the internal membrane 

 lining, the heart and valves, there need be no great wonder if 

 horses are affected in the heart. We have already' pointed out 

 that thickening and dilatation of the walls of the heart is unques- 

 tionabh- due to overexertion or to long-continued exertion that 

 makes excessive demands upon the organ which has to pump the 

 blood over the whole bod\-; bearing in mind, therefore, these two 

 facts, nameh', the susceptibility to rheumatism and the possible 

 consequences upon the heart, and the liability to organic altera- 

 tion in the structure of that organ in consequence of overstrain in. 

 the performance of its functions, the view that we hold regarding 

 the probable combination of all these conditions in one subject 

 does not seem unreasonable. There is an appendage to the valves 

 of the heart which has not been referred to, which might strike 

 anyone making a careful inspection of a heart as a careless omis- 



