300 BOVINE OBSTETRICS 



two cases of such a posterior presentation in practice, where a 

 spontaneous rupture followed violent uterine contractions dur- 

 ing exploration. 



Tapken reports a case of posterior presentation of a calf 

 •with the hind leg retained under the body. While adjusting 

 the parts the cow suddenly made a violent move, followed by 

 a considerable rent in the uterus. 



Spontaneous ruptures usually take place in the floor of the 

 uterus within 10 cm. from the cervix, and always involve all 

 three layers, showing a length of 20 to 30 cm. and more. They 

 may be so large that the calf passes through them, lying free 

 in the abdominal cavity. 



The diagnosis is not difficult. On exploration, the calf is 

 found to have descended and the large intestines are usually in 

 the uterine cavity. Close examination reveals the direction 

 and extent of the rupture. 



Course, prognosis and treatment. — The course is acute. A 

 violent peritonitis or internal hemorrhage usually causes death 

 ■within a few hours. Those ruptures of the uterus which take 

 place while the cervix is closed form an exception. It happens 

 that obliteration of the os uteri is followed by rupture of the 

 uterus and no air entering. Rupture the result of torsio uteri 

 may also occur without entrance of air. Here the course is 

 different. Such animals show the symptoms of an internal 

 hemorrhage or siibacute peritonitis, causing a fatal termination 

 in due time. Since treatment is out of the question, the 

 animal is to be slaughtered. 



Small injuries in the pregnant horn are often produced by 

 rough manipulations while correcting a malposition, or by the 

 slipping of the hook. These small injuries do not exceed 10 

 cm., and differ materially from the spontaneous ruptures. 

 Among others, they may follow reposition of retained hind legs 

 in a posterior presentation, when the fetlock is corded and 

 pulled at, without repelling the foetus or resting the hand 

 against it. In this rough method the fetlock of the calf rotates 

 under the pubis, exerting such pressure upon the floor of the 

 uterus that a rupture may easily take place. Rupture may 



