Rheu til a tism . 535 



Endocarditis is the most frequent, being found in a large propor- 

 tion of fatal cases, and thickening of the valves, vvart-likeexudates 

 and coagula are especially common. The clots may fill nearly 

 the entire ventricular cavity, or at times the auricular, and show a 

 preference for the left side, probablj' because of the more vigorous 

 sj'stole and the higher blood tension. The clots as a rule are 

 firnil}' adherent to the diseased valve. Ulceration of the valve is 

 rare in rheumatism. Otlier parts of the ventricular endocardium 

 may b^ involved, becoming red, congested, rough or thickened, 

 with adherent blood clots. 



Pericarditis is less common though it may exist on either or 

 both the cardiac and visceral folds. It is shown by vasculariza- 

 tion, thickening, fibrinous exudate, and serous effusion. Hay- 

 cock found in a horse a quart of reddish serous exudate with 

 floating fibrous slireds and false membranes. Pus has been found 

 in exceptional cases manifestly indicating a complex infection. 

 Like endocarditis it may precede, follow, or coincide with an ar- 

 ticular attack (Leljlanc, Cadeac). 



Myocarditis is usually seen as a complication and extension of 

 rheumatic inflammation of the visceral pericardium, or of the 

 ventricular endocardium. The muscular tissue may appear par- 

 boiled and friable, and shows granular or fatty degeneration. 



Pulmonic and pleuritic lesions . Embolism of tlie lungs and pleura 

 may occur from the transference of clots from the right heart, 

 yet the .sequence is much more commonly an articular rheumatism 

 following infective disease of the lungs. Cadeac suggests that 

 the impaired nutrition in pneumonic and pleuritic animals pre- 

 disposes to the rheumatic arthritis, and again that the microbes 

 of the infectious chest affection, colonizing the joints and other 

 synovial sacs, determine the rheumatism. This last theor\' has 

 the weakness of identifying influenza and contagious pneumonia 

 with articular rheumatism, and is negatived by the experience 

 that these two pulmonary affections never develop de novo from 

 simple rheumatism. The rheumatism which follows influenza 

 and contagious pneumonia therefore must either be considered as 

 a pseudo-rheumatistn, or a rheumatism occurring only concur- 

 rently and accidently with the pulmonary affection. Apart from 

 this, pleurisy or even pneumonia occurs as a simple extension 

 from a rheumatic pericarditis. 



