428 FCETAL DYSTOKIA. 



In the Mare and other animals there is more room for the passage 

 of the foetus in this position, and with the first-named deHvery may be 

 accompHshed in some cases by guiding the limbs through the genital 

 canal, so as to prevent injury to its walls. 



Dorso-supra-Cotyloidcan Positions. 



In these positions the foetus lies on its right or left side, and they 

 must be altered to the dorso-sacral position before birth can be com- 

 pleted. This change is effected in the same manner as in the pre- 

 ceding position. 



SECTION II.— DYSTOKIA DUE TO THE HIND-LIMBS. 



As Saint-Cyr remarks, it is somewhat surprising to find the hind- 

 limbs an obstacle to birth in the anterior presentation. The difficulty 

 may arise from the hind-limbs being retained by the stifles, the irre- 

 ducible mass of which is greater than the inferior bis-iliac diameter of 

 the inlet ; or the hind-limbs may be bent under the body and enter the 

 pelvis along with it, instead of being extended and following it. In 

 both conditions the anterior part of the body presents in a normal 

 manner, and nearly always in the dorso-sacral position ; and birth 

 appears to be progressing favourably — the fore-limbs, head, neck, and 

 even the chest and body as far as the flanks, may have cleared the 

 vulva — and when the act is apparently almost completed, all at once 

 there is a check, and notwithstanding the most vigorous straining of 

 the mother no more of the foetus can be expelled, neither can external 

 traction remove it. As has been stated above, the retention may be 

 due to one of two causes. 



The Extended Hind-Limhs are retained by their Stifles. 



This kind of dystokia has been hitherto supposed by writers and 

 practitioners to be due to the hind-legs of the foetus being in a state 

 of extreme abduction ; but more careful study has shown it to occur 

 when these limbs are in a state of extension, and their stifles so 

 voluminous as to check progress. This occurrence should be rare in 

 the Mare, unless the pelvis is unusually narrow or the foetus is very 

 large ; but in the Cow it must be more frequent, as the pelvis is not 

 so wide and the shafts of the ilia are more parallel than in the Mare, 

 so that these joints are more likely to be retained when arrested in this 

 way. It is remarked, also, that they are large calves which are being 

 born slowly and with difficulty, that are so fixed when the greater 

 part of their body has got beyond the vulva. 



This cause of difficult birth can be ascertained by exploration with 

 the hand, but the almost complete expulsion of the foetus and the 

 sudden check to its progress, which no amount of traction can alter, 

 should give rise to suspicion of its existence. The obstacle is a serious 

 one to overcome, and it not infrequently happens that the young creature 

 is lost — sometimes the mother also. A successful result depends not 

 only upon the skill and patience of the practitioner, but also upon the 

 size of the foetus when compared with the dimensions of the pelvic 

 inlet, and whether amateurs have been previously at work attempting 

 delivery. 



Indications. — When both stifles are together they form too large a 

 mass to pass through the genital canal, and must therefore be brought 

 into the inlet separately — one after the other. With this object in 



