Obstetrics & Lambing Problems
Clell V. Bagley, DVM, Extension Veterinarian
Utah State University, Logan UT 84322-5600
July 1997 AH/Sheep/12
Lambing season is a busy time and a critical step toward a productive year. The first rule is for frequent observation of ewes due to lamb. Extra help during this season will usually more than pay for the cost because of extra lambs saved.
WHEN SHOULD I HELP?
The cervical dilation period takes 2–6 hours, during which the ewe will be somewhat uneasy (first stage of labor). When the head or feet of the lamb enter the vagina, it stimulates abdominal straining to expel the lamb (second stage of labor). Actual delivery should only require 1/2–2 hours of this straining. If no fetal parts enter the vagina because of problems in positioning, the ewe may not show active straining, but she will show uneasiness and signs of discomfort. The lamb will usually live for 8 to 10 hours after the abdominal straining begins. (See lambing illustrations.)
Examine the ewe if:
1. She has been in first stage labor for 2–3 hours and doesn’t start actively straining.
2. She has been in second stage labor for 1/2–1 hour with little progress.
3. The water sac or membranes have been evident for 1/2–1 hour with little progress.
Confine and restrain the ewe. Be clean. Wash off the rectal-vaginal area as well as your hand and arm. Use a mild soap or shortening as a lubricant. Keep the fingers close together so as not to puncture the reproductive tract. Enter the vagina and identify the cervix, or at least the extent of its dilation; then determine the presentation and posture of the lamb, as well as its relative size.
The “presentation” refers to whether the lamb is coming forwards or backwards. Both of these are normal presentations and you should not turn a lamb around just because it is coming backwards. If cervical dilation is relatively complete, the water bag may be broken, if necessary, in order to examine the lamb. If the cervix is not well dilated, you are probably rushing the process and should allow some more time. If you need a quick anatomy lesson to determine whether you have a front or back leg, compare joint for joint up the leg while looking at the ewe’s leg.
IDENTIFY AND CORRECT POSTURE:
The “posture” refers to placement of the feet and head. In the frontward presentation, the normal posture is for both front feet and the head to be coming together in a “diving” position. In the backward presentation, the normal posture is for both hind feet to be coming together. Deviations from this should usually be corrected before attempting to pull the lamb. If a leg or the head is back, repel the lamb back into the uterus between contractions and manipulate the body parts into proper position. Be careful in pushing the lamb back in so you don’t rupture or tear the uterus. Be patient and apply slow steady pressure. A small lamb may be pulled even with one leg back. Cover the foot or mouth with your hand during manipulation so as not to puncture the uterus with the hoof or teeth. A snare, small rope or o.b. chain attached to the deviated body part will allow a much greater pulling force to be applied than what you can exert with only one hand in the uterus.
Getting the ewe to stand up or elevating her rear quarters off the ground will allow more room for repositioning and result in less vigorous straining.
A true “breech” position is when the lamb is coming backward and both hindlegs are retained in the uterus, rather than extending back into the vagina. It is one of the most difficult to correct. But, the lamb must be repelled forward and then the legs straightened out behind, one at a time.
ESTIMATING SIZE AND DETERMINING LIFE:
The cause of most dystocia (difficult birth) is a lamb that is too large in relation to the dam’s pelvic opening. Excessive stress in pulling and delayed delivery may result in a dead lamb that has to be cut up for removal or taken by cesarean section. The decision to begin pulling or get veterinary help is critical and good judgment is essential. A telephone call and discussing it with your veterinarian is well worth the time and effort. That is also true if you have worked for half an hour without much progress.
Not all lambs will show strong evidence of life, especially after they become fatigued. You can feel for movement, heartbeat and reflexes such as leg jerk, eyelid blink, sucking or rectal pinch.
Obstetrical chains are the most sanitary and most easily applied device for traction. One should be placed on each of the two legs and one (or a snare) on the head. These allow for traction on individual body parts. The head chain should be placed in the mouth and behind the ears to provide better control and to avoid crushing of the wind pipe. It is usually best to have the head chained-up in case it is needed for guiding or traction rather than trying it without and getting into problems, with the lamb partially delivered, because it isn’t ready. Take time to stretch the lips of the vulva back over the head of the lamb, when the head is partially out. This will reduce the tearing of these tissues, as well as reduce the amount of traction needed. Tear up the ewe by rushing at this stage and you’ll pay for it with increased recovery time later.
Be sure to check for another lamb in the uterus after delivery of each lamb. There may be one more in there.
Have some towels available to dry off the lamb; iodine the navel; be sure it gets colostrum within 30–60 minutes; and warm it up if needed. Assist the ewe in standing and keep her off of slick areas if she is wobbly. Clean up equipment and put it back in its storage place. Learn from your experience. Be willing to recognize the problems and don’t be too hesitant to ask for your veterinarian’s advice as well as his assistance. It will result in better profits and less frustration for you. If your herd is experiencing an especially high incidence of problems, you should reconsider your breeding and nutrition programs.