It is rare for ewes to have dystocia. Primiparous ewes often have dystocia due to pelvic stenosis. Others, such as vaginal stenosis, uterine inertia, fetal oversize and abnormal fetal position, can cause dystocia.

When the water breaks for about 20 minutes, the ewe is not responsible, and the fetal membrane has not yet come out, so it is necessary to assist immediately. The main method of midwifery is to forcibly pull the lamb out. The midwife cut her nails short, cleaned and disinfected her arms, and applied lubricant. First, help the ewe expand the vulva, pull out the two forelimbs of the fetus and then send them in. Repeat 3 ~ 4 times, then pull the forelimbs with one hand and hold the head with the other. With the ewes' efforts, slowly pull them back and down, but not too hard. You can also put two fingers into the ewe's anus. Through the rectal wall against the back of the fetal head, with the uterine contraction and pull out, as long as it does not hurt the birth canal, the purpose of midwifery can be achieved.

(2) Several midwifery techniques in dystocia.

When you encounter dystocia, you should judge the reason. You can't just see the tip of your hoof and ignore the fetal position and potential, so you want to pull it out in a hurry. When you see the toes of a hoof, you must first distinguish between forelimbs and hind limbs. If it is an inverted tail position, look at the bottom of the hoof first, with the tip of the hoof below and the back of the hoof above; If it is the position of the head, look at the head and two forelimbs first, with the toes on the top and the back of the hoof on the bottom. When it is difficult to determine, you can touch the knee of the forelimb or the tarsal joint of the hind limb with your finger and distinguish it according to its vertex characteristics.

If abnormal fetal position needs to be restored to normal fetal position, the fetus should be sent back to the uterus. At this time, a long sterile gauze can be tied to the hoof for easy pulling out. The difference is that the forelimbs are not hind limbs. The more common fetal malformations are as follows.

Head sticking out of forelimbs: it may be that the knee of the forelimb extends forward, it may be that the elbow joint bends, or it may be that one forelimb bends the other. At this time, if the fetus is alive and the birth canal is large, you can raise the hindquarters of the ewe, send the fetus back to the uterus, and then pull the forelimbs to the front respectively. During the operation, be careful not to let the toes of hooves touch the uterus and cause trauma. If the fetus is dead, the head is too large or the birth canal is narrow, please ask the veterinarian to cut off the head and dismember it (Figure 9-9).

Figure 9-9 Fetal Potential with Head and Forelegs Protruded

The front legs should not protrude: the head leans backward, bends downward, or bends sideways. If it takes a short time, look for the head first. If the forelimbs have occupied the birth canal, first tie gauze on the hoof and then send it back to the uterus. It is easier to return to normal if the head position is slightly incorrect. If it is obviously abnormal, send the forelimbs as far as possible into the depths of the uterus, reach out and touch the head, and fix the ears, jaws, eye sockets, etc. Correct the position of the head to the normal state by hand (Figure 9- 10).

Fig. 9- 10 fetal potential with forelimbs extended.

Forelegs come out first, and the fetal potential is upward: you can tie the two forelimbs with gauze, gently send them back to the uterus, and reach out to block the fetus, so that the fetus can return to normal fetal potential. If the fetal condition is not corrected, it can be successful to gently pull the fetus to the tail root of the ewe under the responsibility of the ewe.

After the hind legs come out first, the fetal position is upward: first, it is necessary to determine whether the cervical opening is enough. If the opening is not enough, it is necessary to wait for more time to fully open the cervix, and then use the above method to restore the fetal position to normal (Figure 9- 1 1).

Fig. 9- 1 1 upward trend of fetal hind limbs coming out first.

Hip first: first put your hand into the depth of the birth canal to determine the abnormal fetal position, and then push the fetus back to the uterus as much as possible, and operate it with your fingers to restore the normal fetal position (Figure 9- 12).

Fig. 9- 12 potential of the first child in the buttocks

Limbs first: to determine whether it is a single sheep or a pair of sheep. If it is a single sheep and its limbs are tied with gauze, it can be handled in the following two ways. One is to turn the fetus into a tail fetus, keep the gauze of the hind limbs, and send the forelimbs back to the uterus. When using this method, the key is to correctly judge the forelimbs and hind limbs. The other is to replace the fetus with a normal fetal position, that is, keep the gauze of the forelimbs, send the hind limbs back to the uterus, and then gently pull the fetus out with the responsibility of the ewe (Figure 9- 13).

Figure 9- 13 limb potential of the first fetus