DYSTOKIA DEPENDING ON ANTERIOR PRESENTATION. 



451 



all the more serious in the Mare from the fact, as has so often been stated, 

 that obstetrical manoeuvres in this animal are much more difficult than in 

 the Cow : the straining being far more violent, paralyzing arms and hands, 

 while the impatience and restlessness are generally so great, that it is 

 often necessary to throw it down before anything can be done in the way 

 of adjustment. 



Misdirection of the head usually takes place immediately preceding or 

 during parturition, under the influence of irregular and energetic uterine 

 contractions before the os is sufficiently dilated ; it is supposed sometimes 

 to be due to premature escape of the " waters," to injudicious manipula- 

 tion of the fore-limbs, maltraction, etc. Some of fie cases, however, 

 have doubtless occurred long before the period of parturition, and are of the 

 nature of deformity of the neck or head, or both ; we have alluded to 

 them when treating of " Contractions," at page 391. 



It will readily be understood why misdirection of the head should prove 

 a serious obstacle to delivery, when we remember the part the nose and 

 cranium play in dilating the os and genital canal, and how largely this 

 voluminous region must add to the bulk of the neck, and render expul- 

 sion impossible. 



Deviations of the head may be met with in the four principal positions 

 of the anterior presentation ; and they may occur alone, or be complicated 

 with misdirection of the fore-limbs. We will not again refer to these 

 latter, as we have been sufficiently explicit with regard to them, but will 

 now study the head in three different deviations from the normal direction, 

 as given by Saint-Cyr. These malpositions are : i. Downward deviation, 

 the nose being towards the chest, and the " poll " or upper ridge of the 

 neck presenting; 2. Lateral deviation to the right or left side, the head 

 being carried towards the shoulder or flank of that side, the side of the 

 neck presenting j 3. Up7uard deviation, the head being bent up and back- 

 wards in the direction of the withers, or twisted to the right or left side of 

 the chest, with the throat, either straight or twisted, presenting. 



Downward Deviation. 



This is usually the deviation of the head met with in hydrocephalus, though 

 it is not very uncommon when the cranium is normal and the foetus well- 

 formed. The deviation may exist from mere flexion of the head at the 

 atlas — the nose lying immediately in front of the pubic border — to extreme 

 flexion of the whole of the neck, the head being pushed beneath the chest, 

 or even the abdomen. It is only met with in the vertebro-sacral position 

 of the foetus, and more often perhaps in the Cow than the Mare. 



The cause is usually ascribed to premature rupture of the foetal mem- 

 branes, and the deviation occurs when the foetus is entering the pelvis. 

 If the head is not exactly in the axis of the inlet, but inclines a little 



purpose. The head being thus secured, the protruding limbs are pushed forward into the uterus, after a 

 cord has been fixed to each pastern. If the genital passsage is dry, oil is plentifully injected into it. 

 Traction being then exerted on the head, this readily clears the inlet of the maternal pelvis, its dimensions 

 being no longer increased by the addition of the limbs ; it is drawn well into the pelvic cavity, and then 

 the fore-limbs are easily brought through the inlet, now only occupied by the neck of the foetus. , The head 

 and feet are after\\-ards simultaneously drawn towards the vulva, and it is rare, if the traction is judicious, 

 that delivery is not promptly effected. 



Through ha-vnng neglected the precaution of first pushing the fore-limbs into the uterus, Collin, at the 

 commencement of his career, in 1853, lost two Cows. Since that time, in more than two hundred cases, 

 he has been successful in delivering the calf, without resorting to embryotomv. Success is always certain, 

 provided incompetent persons have not previously rendered it impossible. He recommends the same pro- 

 cedure in spasm of the cervix uteri, after reduction of torsion of the uterus, and in.fcEtal hydrocephalus. 

 In the latter, puncture of the cranium is easier if the fore-limbs have been previously pushed into the 

 uterus. 



