414 PRINCIPLES OF VETERINARY SURGERY 



metritis are nearly always the origin of purulent infection. 

 In the ox the disease has been actually observed as the result 

 of compound fractures, accidents of parturition, metritis, ab- 

 scesses from foreign bodies and from traumatic pericarditis. 

 In the hog the disease occurs from castration and in the new- 

 born from infection of the umbilicus. Valley reported a 

 veritable enzootic of pyaemia in new-born lambs. In the dog 

 complicated fractures and crushing of the limbs are the usual 

 causes. 



PATHOGENESIS.— It would be tedious to unfold at 

 length the history of the various conceptions of the subject 

 of pyaemia. We shall only mention those which seem to have 

 enjoyed special favor. Most of the theories aim to explain 

 the formation of metastatic abscesses. Before Boerhaave, 

 Ambrose, Pare, and Morgagni have held to the theory of pu- 

 rulent resorption. Boerhaave in 1720 entertained the theory 

 of penetration of pus into the blood vessels, but his hypothe- 

 sis was .not universally accepted. One hundred years later 

 Breshet and Littre held that pus found its way into the blood 

 by simple osmosis. The theory of phlebitis that succeeds 

 the preceding was generally accepted until recently. It was 

 supposed that the inflammation of the veins caused coagula- 

 tion of the blood on their interior, and that suppuration su- 

 pervened in the clotted blood, and that the blood thus be- 

 came mixed with pus. The studies of Virchow on emboli 

 (1856) partially explained the formation of abscesses. From 

 1869 to 1871, Verneuii engaged in demonstrating the com- 

 mon origin of septicaemia and purulent infection. He proved 

 that intravenous injections of filtered pus-serum caused sep- 

 ticaemia and that inoculations of the solid parts of pus caused 

 pyaemia. To him purulent infection was embolic septicaemia. 

 The recent studies of infectious micro-organisms made 

 Verneuil's theory fruitful and explained the obscure points. 

 The microbian theory has supplanted all the others. Al- 



