464 Veterinary Medicine. 



etc. In swine, beside the common factor rheumatism, tubercu- 

 losis is a frequent cause, also bone and joint diseases, and the in- 

 fectious fevers, especially rouget (erysipelas), and in this con- 

 nection, omphalitis, pyaemia, gangrenous and diphtheritic in- 

 fec^'ions, etc. In dogs, we must bear in mind the special predis- 

 position to heart disease, also to rheumatism and tuberculosis 

 which are both liable to attack the heart. Hunting dogs are 

 especially liable through the great strain thrown on the valves. 

 Again, omphalitis ; bone diseases ; parturient phlebitis ; dis- 

 temper ; infected wounds, operative and accidental ; infective 

 tumors of the digits and elsewhere ; and ulcerous stomatitis 

 have each been the starting point and source of infection in en- 

 docarditis. Hsematozoa must not be overlooked : Strongylus 

 vasorum and filaria immitis, living in the heart blood, are es- 

 pecially injurious. In a recent case of filaria immitis, in a 

 pointer, from Virginia, with forty mature worms in the dilated 

 right ventricle and in large aneurisms on the right pulmonary 

 artery, the blood meanwhile swarming with embryos (i per 

 cubic millimetre), the left flap of the tricuspid valve was repre- 

 sented by an uneven ridge of vegetations only, and the few rem- 

 nants of its cordae tendinse were short and flattened down 

 against the septum ventriculorum. 



In the domestic animals generally, as in man, the heart valves 

 are a favorite seat of different microbian infections of very 

 varied kinds. Anaerobic organisms are, in the main, debarred 

 on account of the oxygen in the blood, and the left heart, with 

 its more highly oxygenated blood is the most common seat of 

 the infection. Lion claims that in foetal puppies ulceration of 

 the valves is more common on the right side, which in intra- 

 uterine life receives the most highly oxygenated blood. 



In the early stages there may be a mere swelling of the valves, 

 with as yet a smooth, unbroken surface, but with enlargement 

 and increase of the connective tissue cells, later fungous vegeta- 

 tion starts out from the surface, and on these fibrine of the 

 blood is deposited in layers. 



Besides the formation of clots on their surfaces other changes 

 occur on the cardiac valves as the result of inflammation. The 

 organization of the exuded lymph within and upon them leads to 

 rigidity, loss of elasticity, uneven&ss of their surface, contrac- 



