3o6 Veterinary Medicine. 



oxygen in every case of milk fever, reduced the mortality to a 

 fraction of one per cent. Finally the injection with simple 

 sterilized air proved equally effective and deaths came to be con- 

 sidered as extremely improbable even in very bad cases. This 

 points unequivocally to the arrest of the formation of leucomaines 

 by the reduction of the circulation in the udder. The extreme 

 distension of the milk ducts and follicles by bland gas, or liquid, 

 compresses the vessels in their walls and reduces the flow of 

 blood. With this reduction of the circulation comes the arrest of 

 the formation of the toxic leucomaines and of their absorption. 

 When the poison no longer reaches the nerve centres in danger- 

 ous quantity the nervous disorder, and collapse are prevented or 

 corrected. This hypothesis explains every phenomenon and is 

 obviously the right one. 



Microbian Infectio7i or Intoxication. This has been of late a 

 favorite hypothesis, apparently sustained by the sudden and pro- 

 found prostration of the nerve centres, the notorious prevalence 

 of milk fever in given hamlets, and the occasional arrest of the 

 disease in a herd, by moving the parturient cows to a previously 

 unoccupied stable and holding them there until nine days after 

 calving. But on the other hand the disease occurs in the strong 

 plethoric cow, not in the impoverished one which should have 

 less vital resistance ; it follows the easy unassisted parturition in 

 which there has been no chance for the introduction of bacteria 

 by the womb nor any shock nor exhaustion to render the system 

 more susceptible, while it respects the cases of difficult parturition 

 with abundant introduction of microbes on hands and instru- 

 ments ; no inoculation from the womb upon another parturient 

 cow has produced the disease ; finally, if it were due to the ab- 

 sorption of microbes or their toxins from the milk in the udder 

 the bacteria should be increased in the abundant lacteal culture- 

 medium and the absorption of the toxins more active from the 

 tense and overfilled milk ducts into the relatively more flaccid 

 blood vessels, whereas the simple overdistension with milk is the 

 best prevention of the disease. The mere presence of cocci or 

 bacilli, which are by no means constant, nor always of the 

 same species in cases where they do occur, can mean nothing as 

 causative factors in the face of the above facts. In short, bac- 

 teridian infection of womb or udder must be eliminated from the 

 list of essential causes. 



