Labor & Dystocia in Alpacas: A Technician's Role
ACVIM 2008
Shirley Sandoval, AAS, LVT
Pullman, WA, USA

Introduction

Veterinary technicians are often the first veterinary professionals to triage telephone calls from distressed camelid owners concerned with their pregnant hembras. A thorough knowledge of pregnancy, parturition and neonatal care is essential to assist both the breeder and the veterinarian in triaging pregnancy related problems. If the animal is thought to be in dystocia, and the client is unable or ill prepared to correct it, the animal should be immediately transported to the veterinary hospital. Once the alpaca is in route or present to the practice, the technician needs to be able to anticipate the procedures to be performed and the equipment required. Technicians should also be prepared for the possibility of general anesthesia, caesarian section and the resuscitation of the cria. Finally, technicians are actively involved in post partum, neonatal and intensive nursing care of these patients.

Gestation Parameters

The average length of gestation in the alpaca is 345 days with a range of 335-372 days. However, the season of breeding can affect the length of gestation with dams bred in the spring going longer than dams bred in the fall. A dam's previous history can also give an idea of the gestation length in individual animals. Crias born before 330 days are considered premature and amongst their difficulties is respiratory insufficiency due to lack of pulmonary surfactant.1

Stages of Labor

Labor has three stages. Stage one is the most variable stage as there are few noticeable signs to this beginning of labor. This stage is initiated by the inability of the uterus to support the size of the fully developed fetus. The fetus releases adrenocorticotropin as it becomes stressed and hypoxic. This in turn stimulates the fetal adrenal cortex to produce corticoids, in particular cortisol. The cortisol promotes the placenta to synthesize more estrogens. The placenta also produces prostaglandin F which in combination with the estrogens initiates the contractions of the myometrium. The prostaglandin production also causes regression of the corpus luteum which decreases the progesterone levels need to maintain the pregnancy. All of these events combine to position the fetus within the pelvic cavity, facing the cervix. The pressure of the fetus against the cervix initiates stage two of labor.

Stage two is defined as the time from the rupture of the allantochorionic sac until the expulsion of the fetus. In the alpaca, this stage should be completed in less than one hour. The allantochorionic sac is normally not visual at the vulva, but ruptures within the uterus. The amniotic sac is what is noticed at the vulva after the initiation of stage two labor. It must be ruptured before any fetal parts will be visible. Normal parturition has the fetus presenting with the forefeet and head first. Dams usually give birth standing allowing for gravity assistance of the deliver and draining of fetal fluid from the crias respiratory tract.

Stage three labor is the expulsion of the placenta. It should be completed within 3 hours of the birth of the cria and normally occurs in 30-45 minutes. The placenta should be examined to ensure the entire placenta has passed and to detect possible infectious process.1

Dystocia Parameters

A dystocia should be considered if stage one labor lasts more than 6 hours, or if the allantochorionic sac ruptures, but no visible progression has occurred within 10 minutes, if the amniotic sac is seen, but the birth does not progress in 10 minutes, if the cria is visible, but the birthing progress stalls for more than 10 minutes. Other signs of dystocia could include colic, excessive straining, giving birth in the late evening or during the night (South American camelids normally give birth during mid morning to mid afternoon). Dystocia may be caused from a multitude of problems, but it is attributed to either the dam or the fetus.2

Dystocia Due to Maternal Origin

Some maternal causes of dystocia include failure of the vulva or cervix to dilate. This may be due to the fetus not engaging in the pelvis correctly so the appropriate pressure is not applied to the cervix to assist in dilation. Uterine torsion may occur in the last few months of gestation, causing the animal to become acutely and severely painful. Rarely, there will be a maternal/fetal disproportion problem, but a caesarian section should be considered for both a live or dead cria to give the dam the best chance at returning to a reproductively productive animal. Finally, uterine inertia which is a result of prolonged labor and an exhausted dam. Assisted vaginal delivery is compounded in these animals as the uterus is not contracting to help expel the fetus, so progression is based only on the manual expulsion.2

Dystocia Due to Fetal Origin

The most common cause of dystocia in camelids is due to fetal malposition, with deviation of the head and/or limbs being the major infraction. The presentation, position and posture of the fetus are used to describe the specific fetal orientation within the uterus.

Presentation describes the relationship between the long axis of the fetus and the long axis of the dam's pelvic canal. Normal presentation is described as longitudinal anterior (headfirst) or longitudinal posterior (hind limbs first). Abnormal presentations include dorsal transverse or ventral transverse, presenting the back or the abdomen, causing dystocia.

Position describes the orientation of the vertebral column of the fetus with respect to the birth canal. The normal position is dorsosacral (back of the fetus towards the dam's sacrum). Abnormal positions would include dorsopubic (upside down) or dorsoiliac, tilted to the right or left.

Posture describes the position of the fetal appendages, head and neck, with respect to the birth canal. The limbs should be extended, as are the head and neck during normal parturition. Lateral, ventral or dorsal deviation of head and neck are causes of dystocia, as are various degrees of flexion of the limbs over or under the fetus impeding progression of the fetus through the birth canal.2

Assessment

Upon arrival, assessment of the dam and fetus should be ascertained. The tail should be wrapped and if there are no fetal parts visual in the vagina, transrectal palpation by the veterinarian may rule out a uterine torsion, determine the position of the fetus, and allow for uterine contraction assessment. Next, after through cleaning of the perineal area with mild soap and water, vaginal palpation to assess the dilation of the cervix, feel for uterine torsions or other vaginal trauma and fetal positioning should be performed. Evaluating the pelvic size and dilation of the birth canal can also be determined at this time.

Transabdominal ultrasound to assess the fetus may require clipping a large area of the abdomen. The heart rate of a stressed fetus may be high (above 120 bpm) or low (below 50 bpm) depending upon the duration of the stress. In the last month of gestation, normally the fetal heart rate should decrease from twice the rate of the dam to about the same as the dam.2

For an animal with uterine torsion, the severity of compromise of the uterus is an important factor. A laparotomy may be performed to correct the torsion, with subsequent caesarian section if the fetus is term or dead. Another less invasive procedure readily described in the literature is to roll the animal to de-torse the uterus. This may or may not require the use of sedation or anesthesia on the dam and a few people to assist in the rolling.

When assisted vaginal delivery is attempted, it is imperative to monitor the time. All fetal manipulations should be performed and the fetus expelled within a 20 minute window. If the fetus cannot be delivered in this timely manner, a caesarian section should be performed. Repetitive or prolonged manipulations through the cervix may result in cervical lesions or vaginal adhesions. This in turn may result in the inability of the dam to conceive or maintain subsequent pregnancies.2

Due to their small size and the frequency of trauma to the cervix, fetotomies are not recommended in alpacas.1

Anesthesia

Epidural anesthesia may be helpful with examination of the alpaca who is severely straining or in need of analgesia.

Regional anesthesia is used if the dam is severely compromised and general anesthesia is not an option or surgery is required in the field.

Induction and general anesthesia pharmaceuticals should be chosen carefully to avoid compromising the fetus as many products cross the placenta.

Caesarian Section

The surgeon will make a decision between a flank or midline approach given the condition of the animal and the available resources. The technician needs to be prepared to proceed with either approach in a timely manner and assist in keeping the total anesthesia time for the cria to a minimum.

Cria

Once the cria is born and passed off to a non-sterile person, the cria should be held with the head lower than the lungs to assist in relieving the cria of fluid in its lungs. The cria should be examined for a heartbeat and any respiratory activity. Excessive fluid may be aspirated from the mouth and trachea. An oxygen mask should be applied until the cria is alert and responsive. The use of respiratory stimulants can be used to promote respiratory effort in these anesthetized neonates. Stimulation of the cria by removal of the epidermal membrane and toweling dry then placing them on a circulating water pad will assist the cria in maintaining its temperature. Examine the alert cria for a suckle reflex, and access the fetal maturity. Give the cria colostrum either milked from the dam or from an alternative source as soon as the cria exhibits an interest in nursing. If the cria is not interested in nursing after an hour, it may be necessary to initiate feeding of colostrum via an orogastric tube.1

If the fetus is dead upon presentation, treat it as if it were an Dystocia due to material origin

Some maternal causes of dystocia include failure of the vulva or cervix to dilate. This may be due to the fetus not engaging in the pelvis correctly so the appropriate pressure is not applied to the cervix to assist in dilation. Uterine torsion may occur in the last few months of gestation, causing the animal to become acutely and severely painful. Rarely, there will be a maternal/fetal disproportion problem, but a caesarian section should be considered for both a live or dead cria to give the dam the best chance at returning to a reproductively productive animal. Finally, uterine inertia which is a result of prolonged labor and an exhausted dam. Assisted vaginal delivery is compounded in these animals as the uterus is not contracting to help expel the fetus, so progression is based only on the manual expulsion.2

Post op

Most alpacas recover quickly from inhalant anesthesia and are usually mobile 15-30 minutes post extubation. These animals should be kept warm and introduced to their cria as soon as possible to promote bonding. Post-operative antibiotics and analgesics are at the discretion of the attending veterinarian. The incision site should be monitored regularly. Ventral midline incisions should be covered with a bandage as these animals commonly rest in a "cushed" position.

Post Partum

The dam should be examined for passage of the placenta, any vaginal or cervical trauma and if there is a prolapse. Lactation production should also be monitored to ensure adequate nutrition for the cria.

The cria should receive a physical exam post partum. In addition to temperature, pulse and respiration, the cria should be weighed to follow colostrum intake. Finally, the cria needs to be monitored for the passage of meconium. Failure to pass meconium may require a warm soapy water enema; however, routine enemas are not recommended.2

References

1.  Sandoval S. Vet Tech 2006; 27(8): 490.

2.  Tibary A. The Complete Alpaca Book 2003; chpt 14: 382

Speaker Information
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Shirley Sandoval, AAS, LVT
Washington State University
Pullman, WA


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