242 



her to enjoy the pleasure of Ucking and cleaning it with her rough 

 tongue. Thirdly — Through excitement and shock caused by the with- 

 drawal of all the milk, at once, either before or after calving, thus 

 removing the pressure too suddenly, this in turn inducing paralysis of 

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

 the nervous S3''stem. 



577. If 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 

 materials which enter into the composition of the " colostrum," 

 or " beastings,'" which are, 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 bod}^ by the action of the udder. 

 But, as the udder is not working, these elements are retained in the 

 circulatory system, acting there not only as a foreign body, but 

 assuming a toxic action, affecting the nerve centres, and causing the 

 peculiar excitement seen in the early 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. 



578. 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 recognisable prior 

 to calving, particularly if the cow, owing to the great distension of 

 the udder, has been milked. The first symptom to be noticed is a 

 thoughtful expression of the face, manifested by a peculiar holding up 

 of the head, and pointing out of the nose, while the eyes stare right 

 in front ; there is also paddling of the hind legs, and switching 

 of the tail, while the animal staggers about the stall with a 

 spasmodic rigid twitching of the muscles, in the region of the stifles, 

 which seem to be pulled backwards, and to a certain extent, are beyond 

 control. This is followed by a stage of excitement, when the animal 



