354 VETERINARY LECTURES 



any breed are liable to it, especially if at grass, when its effects are 

 more fatal than when they are fed on dry food indoors ; it is, how- 

 ever, not so frequent nor yet so fatal when cold east winds prevail. 

 Moreover, it seldom follows where there has been any difficulty in 

 calving, it being most common when the cow has calved without 

 any assistance. The real cause of this so-called milk fever is not yet 

 exactly known. My opinion is that it is due to a succession of shocks 

 to the system: first, through the easy expulsion of the waters and calf 

 from the womb ; secondly, through the removal of the calf from the 

 presence of the mother, and not allowing her to enjoy the pleasure 

 of licking and cleaning it with her rough tongue ; thirdly, through 

 excitement and shock caused by the withdrawal of all the milk at 

 once, either before or after calving, thus removing the pressure too 

 suddenly, which is the whole crux of the matter, this in turn inducing 

 paralysis of the milk cells, a total cessation of the milk secretion, and 

 collapse of the nervous system. 



581. The paralysis of the milk-producing parts of the udder is 

 caused by the sudden withdrawal of all the milk at once, then the 

 nervous power is impaired by the pressure being too quickly removed, 

 and the secretion of milk is thus suspended It stands to reason 

 that the elements entering into the composition of the ' colostrum,' 

 or ' beastings,' which are of a nitrogenous nature, and at this time 

 contained in the system of the cow — more particularly if the animal 

 is a deep milker — would naturally be eliminated from the body by 

 the function of the udder. But as the udder is not acting, these 

 elements are retained in the circulatory system, where they not only 

 act as a foreign body, but have a toxic effect on the nerve centres, 

 and cause the peculiar excitement seen in the eariy stages of the 

 derangement, this excitement being succeeded by total prostration 

 of the whole nervous system, in which all the organs of the body 

 participate, and is followed by congestion of the structures. 



582. Symptoms. — As a rule, milk fever symptoms are noticed from 

 about four to six hours after the second milking, or from a few hours 

 after calving up to, say, the fifth day, or until the beastings are 

 cleared out of the system. Occasionally the symptoms are recog- 



