C— ABNORMAL PREGNANCY. 



I. 

 DISEASES AND ACCIDENTS OF PREGNANCY. 



1. — Circulatory Disturbances. 



Already when dealing with pregnancy it was mentioned 

 that the total amount of blood in the mother increases during 

 development of the young. In consequence of it, an active 

 dilatation or eccentric hypertrophy of the left heart takes 

 place. This hypertrophy develops so gradually that no dis- 

 turbances arise in spite of the greater efforts which the heart 

 must make to propel the increased amount of blood over the 

 body. The annually occurring pregnancy of the cow, desirable 

 from an economic standpoint, conception taking place two or 

 three months after the stage of involution, often leads to a 

 permanent hypertrophy of the left heart. In old milch cows 

 one frequently meets with hypertrophy of the left heart, this 

 condition never having caused any disturbances during life. 



In the pregnant animal, swelling of the udder begins at 

 the eighth month of gestation. This occurs a little sooner in 

 cows which have calved frequently and have been dry for quite 

 some time. In primiparse the swelling of the udder begins 

 four to six weeks before parturition and increases up to birth. 

 Many breeders look upon this tumefaction as a favorable 

 indication for milk production. The swelling confines itself 

 at first mainly to the posterior quarters, but may extend later 

 to the anterior half of the udder. 



This swelling before birth is physiological ; it may extend 

 to the vulva and anteriorly to the umbilicus. 



The tumefaction of the vulva, often so intense that the 

 skin becomes glistening and tense, is not caused by a disturbed 



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