Parturition and Dystocia in the Goat

CHAPTER 73 Parturition and Dystocia in the Goat



WILLIAM. BRAUN, JR.



PARTURITION


Parturition is signaled by a series of events in pregnant does that alert the owner to impending kidding. Relaxation of the pelvic ligaments, as a result of an increase in circulating estrogen levels in late gestation, warns the owner that kidding is imminent. At about the same time, the vulva enlarges and may become slightly longer. In most goats there is a rapid enlargement and engorgement of the udder as well, although udder enlargement may not be an accurate indicator of impending parturition, as first fresheners may initiate udder enlargement as early as the third or fourth month of gestation. Some does have early engorgement of the udder to the point that milking is required. Other does do not show udder enlargement until the point of, or just shortly after, parturition.


As in other species, parturition is divided into three stages. The first stage is the initiation of myometrial contractions as progesterone levels drop and estrogen levels increase. In first fresheners, this stage may last from 2 to 12 hours. Pluriparous does may show very little discomfort, and the first stage may last only a few hours. The doe is restless and most signs are reflective of abdominal discomfort. She will lie down and rise, paw at the bedding, and maybe urinate or defecate in frequent, short bouts. During this period, the cervix relaxes and releases the cervical seal that is seen at the vulva as thick, tenacious, yellowish brown mucus. The contracting uterus pushes the placenta, fetus, and fetal fluids toward the cervix, further dilating it.


When the placenta and its contents fully dilate the cervix and come into contact with the vagina, second stage labor is initiated with the concomitant abdominal press that is characteristic of active labor. Depending on the number of fetuses present, this stage will last from 1 to 3 hours, with most does delivering all fetuses within 2 hours. Does typically are in lateral recumbency during this stage, but some older, more experienced does may remain standing for delivery. After the placenta reaches the vagina, the chorioallantois ruptures, lubricating the vaginal canal, and the amnion, or water bag, is partially delivered through the vulvar opening. This also ruptures and the kid is delivered. In multiple births, the doe may rest between deliveries, or they may occur one after the other.


Third stage parturition is characterized by delivery of the placenta or placentas and involution of the uterus. In the goat, the placenta is usually delivered within 1 hour of kidding and is considered retained if not expelled by 12 hours. In some multiple births, placental expulsion may be intermingled with delivery of kids. The mass and volume of the postpartum uterus decline drastically from delivery until about day 12 post partum.1,2 Involution is macroscopically complete by day 28 post partum. The rapid decline in mass and volume of the uterus is ascribed to contraction of the myometrium together with vasoconstriction and loss of tissue fluids.2 Lochia is normally discharged for up to 3 weeks. This is a nonodorous, reddish brown discharge that represents the debris remaining in the uterine lumen from parturition as well as some of the residual tissue and fluid from uterine involution.



DYSTOCIA


Normally, delivery is uneventful in goats. Dystocia exists when delivery is prolonged or some event occurs that makes delivery difficult or impossible. The number of cases that require obstetric assistance is low, with only 3% to 5% of births requiring help.3 Most birthing problems are handled by owners and only the more difficult cases are submitted for veterinary assistance. Dystocia is considered to exist if the doe has been in active labor for 30 minutes or longer and is not making progress toward delivery of the kids.4


Most kids are born in cranial, longitudinal presentation, dorsosacral position with extremities extended, like cattle. Some 3% to 9% of kids are born in caudal, longitudinal presentation, almost all in sets of twins or multiples.3 The incidence of dystocia is higher, on a percentage basis, for births in caudal presentation in goats.3 In caudal presentations, 80% of the single births had one or both hindlimbs flexed.5


The most common dystocia arises when more than one fetus tries to exit the vaginal canal at the same time.4 This tangle of kids is often separated by skilled owners. Other causes of dystocia are deviations from normal presentation, position, or posture, fetomaternal disproportion, failure of cervical dilation (ringwomb), vaginal prolapse, uterine torsion, and uterine inertia. Dystocias are commonly seen in Nubians because of multiple births; in first freshener Saanens that often have a single, large fetus6; and in pygmy goats that are too short-coupled to allow the fetus to properly position itself. One study reported that of 43 cases of fetal dystocia, 3 were caused by fetal oversize, 29 by disposition errors, and 11 by simultaneous presentations.7



Case Management


The diagnosis of dystocia is based on the owner’s observation of the kidding process. This observation may include failure of active labor to be initiated after an appropriate time span, prolonged labor without producing kids, abrupt cessation of parturition, prolapse of portions of the reproductive tract, delivery of the placenta without delivery of kids, or a sense of anxiety that all is not going well. The veterinarian should supplement the owner’s observations with historical information such as expected due date, problems during previous kiddings, parity of the doe, assistance already rendered, and any other information that the circumstances may warrant. Many owners have more experience in handling caprine dystocias than the veterinarian, and if assistance is requested, it is often in cases that require cesarean section. The length of time that the doe has been in labor is important. The cervical canal appears to remain dilated for a much shorter time period in goats than in sheep.3 If delivery has not been accomplished within 2 to 3 hours, the cervix starts to close.


Examination of the doe and all manipulative procedures should always follow the general principles of veterinary obstetrics: cleanliness, lubrication, and gentleness. Does can be restrained in a stanchion or by a halter, or held by the owner. The perineal area is cleansed with soap and water, as are the hands and arms of the obstetrician. Examination of the reproductive tract in goats can be difficult because of the small size of the animal. Epidural anesthesia may be beneficial to prevent straining during examination or the subsequent manipulations. Some large breeds of goats will accommodate manual exploration of their tract all the way into the uterus, if the obstetrician has hands and arms of an appropriate size and plenty of lubrication is employed. Pygmy goats are more problematic and may only allow digital exploration of the vagina. In some cases in which no fetus or placenta is presented, a speculum examination of the vagina is in order. In any event, extreme care must be exercised, as the uterus and vagina are fragile and can be easily ruptured. After physical and visual examination, a diagnosis of the cause of dystocia can be made and a plan formulated for relief. The relief of dystocia includes untangling multiple kids, mutation of maldispositions, traction, partial fetotomy, and cesarean section.

Related posts:

  1. Control and Synchronization of the Estrous Cycle and Ovulation
  2. Bacterial Diseases of the Fetus and Placenta Associated with Fetal Loss in the Mare
  3. Diseases of the Reproductive System of the Bull
  4. Surgical Correction of Abnormalities of Genital Organs of Cows

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Sep 3, 2016 | Posted by in SUGERY, ORTHOPEDICS & ANESTHESIA | Comments Off on Parturition and Dystocia in the Goat

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