Acute Sero-Fibrinous Pleurisy in the Horse. Pleuritis. 319 



ing the limbs in ice cold water as in wading a tiver (Fromage), 

 standing in snow and, above all, in salted snow, or facing a cold 

 rain, sleet, or snow when perspiring or fatigued, are recognized 

 causes. A full drink of ice cold water when freely perspiring, 

 and followed by standing in the frosty air, or in a cold current in- 

 doors. Exposure unblanketed after clipping in winter (Field, 

 Trasbot) , and even sponging the body or legs with cold water 

 when heated, or fatigued, or both. St. Cyr found that pneumonias 

 stood to pleurisies as 3 : i, Trasbot as 10 : i, yet the latter draws 

 attention to the fact that in cavalry horses habituated to the stable 

 and sent out into camps in the depth of winter, the pleurisies are 

 more numerous than pneumonias. This may suffice to show the 

 importance of the r61e filled by cold and chill in the production of 

 pleurisy. Yet many physicians look upon the chill as a predis- 

 position only, while the true origin of disease is microbian. And in 

 man a large proportion of pleurisies appear to be distinctly tuber- 

 culous. Bowditch traced 99 cases of acute pleurisy and found that 

 32 afterward proved tuberculous. In Germany 13 out of 15 pleu- 

 ritic persons reacted under tuberculin. City water injected pro- 

 duced pleurisy (Leblanc and Trousseau). The objection to gen- 

 eralizing too largely on this for the lower animals is that the 

 horse and dog, in which tuberculosis is rare, are by far the most 

 common subjects of pleurisy, whilst cows which are very prone 

 to tuberculosis show few cases of simple pleurisy. Again, we 

 find pleurisy in the horse as the result of other diseases localized 

 in or adjacent to the pleura, and where there is nothing to indi- 

 cate tuberculosis. Thus it follows pneumonia approaching the 

 surface of the lung, cancers, actinomycosis and other tumors, 

 and traumas — a pulmonary abscess bursting into the pleura, a 

 broken rib scratching and lacerating the lung, a perforating 

 wound of the intercostal space, or in cattle a sharp pointed body 

 advancing from the reticulum toward the heart. 



But the presumptive absence of the tubercle bacillus in the 

 great majority of pleurisies in the horse does not prove the absence 

 of all pathogenic microbes. Trasbot, who rejects the microbian 

 theory, found that the injection of a little of the exudate into the 

 pleural cavity of a sound horse, always determined a generalized 

 pleurisy. Injections of distilled water or the fluid of hydrothorax 

 with the same antiseptic precautions, made separately by himself 



