752 Veterinary Obstetrics 



5. The Dystokia of Twins. 



Twins occasionally induce dystokia, and may at times cause 

 confusion in diagnosis. 



The diagnosis of twin or triplet pregnancy, when dystokia oc- 

 curs, is usually not very difficult, especially if the fetuses have 

 not become impacted in the pelvic canal, so that they are immov- 

 able. When they produce dystokia, it is usually because one or 

 more extremities of each fetus has entered the pelvic canal. 



A little carelessness may lead to an error. If one fetus is pre- 

 senting posteriorly and the other anteriorly, there may be present 

 in the passages the head and one forefoot of one fetus and one 

 hind foot of the other fetus. This latter may be mistaken for a 

 fore-foot of the former, or other similar error be made if proper 

 care is not taken. 



In other cases there may be such a deformity of a single fetus 

 that it may be mistaken for twins. Especially is this the case in 

 campylorrhachis, which we have already described on page 744. 



The differentiation between twins and double monstrosities is 

 usually not difficult. In case of double monstrosities the two 

 parts necessarily move in harmony ; they advance or retreat 

 together, and each movement that one is caused to make is at once 

 accompanied by a corresponding movement of the other. This 

 is not true of twins. 



The indications for handling dystokia due to multiparity are 

 comparatively simple. The operator needs repel one fetus, or 

 rather the presenting parts of one fetus, and advance the other. 



It is essential that the one fetus shall be repelled entirely into 

 the abdominal cavity, and kept there until the pelvic canal is 

 fully occupied by the fetus which is being advanced, after which 

 it is delivered. The other is then brought into position, and 

 also extracted. Deviations of the extremities of twins are 

 subject to the sailie rules as those of single pregnancies. Twins 

 are usually smaller than single young, and permit of easier 

 handling and correction of position. 



