434 FCETAL DYSTOKIA. 



genital canal ; and if only one appears along with the head, or if the 

 latter alone offers, then one or both of the anterior limbs are in a wrong 

 direction, and birth may be hindered if they are not adjusted. The 

 directions they may assume are generally four : 1. They may he in- 

 completely extended in the loelvis ; 2. They may be crossed over the neck; 

 3. They may he hent at the knees ; 4. They may he extended covipletely 

 under the fcet^is. Each of these misdirections may be met with in the 

 four principal positions of the anterior presentation, and, as has been 

 mentioned, one or both limbs may be involved ; if the latter, then the 

 direction may be the same or different. 



The cause of misdirection of the limbs is not well ascertained. In 

 many cases it may be due to insufficient dilatation of the os uteri, 

 which hinders their advancing with the head : the joints of the limbs 

 readily flexing when the feet come in contact with the cervix, while 

 the uterine contractions propel the more rigid head and neck into the 

 vagina. The misdirection may also primarily occur during intra-uterine 

 existence, and before parturition sets in, and particularly if the foetus 

 dies before birth, when its position is not the same as at that period. 

 There can be no doubt, however, that the accident generally happens 

 during parturition. 



One or Both Fore-Limbs crossed over the Neck. 



This complication is not very uncommon in the Mare, but is less 

 frequent in the Cow ; it usually occurs when the foetus is in the dorso- 

 sacral position. One or both limbs may be carried over the neck, but 

 it is generally only one. 



It is undoubtedly, in many instances, an obstacle to parturition, as 

 the shoulders are no longer lodged in the hollow space at each side of 

 the neck, but are fixed at the side of the chest, the transverse diameter 

 of which they increase. The obstacle is still greater if one or both of 

 the limbs should chance to cross towards the summit of the head. At 

 all times the complication is more serious if the labour pains are 

 violent and irregular — as they generally are in the Mare when there is 

 any impediment to birth ; then there only too frequently results lacera- 

 tion of the roof of the vagina, perforation of the rectum, rupture of the 

 perinseum, etc. In the most favourable cases, labour is protracted and 

 more severe, and contusions of the genital canal are almost unavoidable. 

 In some cases birth may, and does, take place without assistance. 

 Eainard alludes to the case of an Ass in which spontaneous delivery 

 occurred, notwithstanding the existence of this complication. 



The obstacle is discovered by exploring the genital canal, when the 

 hand will encounter in the vagina the head of the foetus and one limb 

 in the usual situation (if only one be misplaced), and the other limb 

 feeling as if shorter, higher up, and crossing the neck towards the 

 fetlock-joint. This is the usual state of affairs. 



Indications. — When only one limb is crossed, reduction is not difficult, 

 and may be effected in the pelvis. The leg is seized a little above the 

 fetlock, raised, drawn to its proper side, and extended in the genital 

 canal. Delivery may then take place without help, or gentle traction 

 on the head and limbs may be necessary. 



"When both fore-limbs are crossed, and the foetus is not too far 

 advanced in the pelvis, cords should be fixed to the pasterns, and the 



