Abstract

Four posterior presentations have occurred among 14 giraffe births at Albuquerque Biological Park (ABP) from 1977–1997. Thirty-four other dystocia cases were identified from a survey of North American zoological institutions for the same years. These 38 cases varied in clinical severity from mild, self-correcting problems to major life-threatening conditions, including eight fatalities among the dams. The cases were grouped into three clinical categories which reflected the complexity of the dystocia and relative risk to the dam. The first group of 15 complex cases required full restraint of the dam, obstetrical manipulation of the calf, and had significant risk for the dam. The second group of seven intermediate cases were managed by no restraint or brief chemical restraint of the dam, were resolved by simple traction without obstetrical exam, and had moderate risk for the dam. The third group of 16 uncomplicated cases were managed with no restraint or brief chute restraint of the dam, had little or no obstetrical work, and minimal risk for the dam. Use of a standing restraint chute to control the dam greatly increased its chance of survival when compared with chemical immobilization to resolve dystocia. Prolonged second stage of parturition, referred to as delayed labor, may be confused with dystocia in deliveries extending beyond 4 h.

Introduction

Reproduction and parturition in giraffe are described in general terms in the literature.^2,4 Some unusual characteristics include a long gestation of 15 mo and birthing from a standing position by the parturient dam. Births occur in all months of the year, most commonly during daylight hours, and normal fetal presentation is craniolongitudinal with dorsosacral positioning.³ Calving is normally completed within a few hours of the start of second stage labor² and was reported in one study to vary between 20 min and 3.5 h⁴. There are few published reports of dystocia,³ yet four cases of posterior presentation occurred among 14 births at ABP between 1977 and 1997. Dystocia cases identified by a survey of North American zoological institutions and the cases from ABP, including observations of prolonged second stage labor, are presented in hopes of aiding in the evaluation of ongoing parturition and resolution of dystocia in giraffe.

Survey

Ninety-three North American zoological institutions house giraffe (all subspecies), according to the International Species Information System (ISIS) Abstracts. Seventy-one of these institutions responded to a questionnaire (76% response rate) and identified 34 additional cases of dystocia between 1977–1997. A follow-up questionnaire yielded more detailed information for each dystocia case. The information presented here is from these cases and ABP experience. A search of ISIS data indicates 1254 giraffe were born in North America during the same years.⁶

Dystocia

The 34 births reported as abnormal parturitions from the survey included 23 cases of fetal dystocia, three cases of maternal dystocia and eight reports which could not be classified as either a fetal or maternal abnormality. A number of factors determined how these cases were managed, including the type of dystocia, the perceived degree of risk to the dam or calf, tractability of the dam, prior reproductive history of the dam, the presence or absence of a restraint chute, and the relative risks of immobilization. ABP cases are described and classified similarly.

Complex Cases

These cases were managed by full restraint of the dam using chemical immobilization or a restraint chute. They required direct obstetrical exam and a corrective obstetrical procedure. Each case posed significant risk to the dam from physiological stress, injury, or prolonged restraint time. There were 14 reported cases of dystocia which fit this description. All were fetal dystocias of which 11 represented malposition or malpresentation abnormalities.

Eight of the complex cases required full chemical immobilization of the dam (seven using xylazine and etorphine¹ and one with etorphine alone). The first five dams described in this series were immobilized after 6–8 h of labor and three of the five dams died due to complications from the immobilization. The first case occurred after a fetal malposition (head flexion) was corrected and the calf pulled. During recovery, the dam fell over backward, sustaining a cervical fracture, and later died. The second dam died at the conclusion of a difficult obstetrical procedure involving a limb flexion, which could not be resolved by either repositioning or by fetotomy. A C-section was performed as a last resort, but the dam aspirated at the completion of the surgery. The third case in this series involved a dam that regurgitated at the conclusion of an immobilization to relieve a hip lock. The dam and calf initially survived the immobilization, but the dam later died from aspiration pneumonia and the calf was subsequently lost as well. The fourth and fifth cases were both successfully managed during immobilization, one required repelling the calf to straighten a flexed forelimb and the other to correct a minor malposition of the calf’s head. Although both calves were born alive, neither survived, but both dams returned to breeding.

The sixth case in this series, a dam with a posterior presentation, was immobilized after 24 h of unsuccessful labor and a fetotomy was successfully performed. The seventh case involved a dam late in gestation that became briefly entrapped in electric fence wire. Thirteen days later a bloody vaginal discharge was noted along with periodic mild straining. Amniotic fluids were passed after an additional 4 days but contractions were mild and produced only more bloody fluid. The dam was immobilized 36 h later and a fetotomy of a decomposing fetus with the head, neck and one forelimb flexed was attempted. The dam died 2.5 h into the procedure. The final case in this series also was immobilized 36 h after labor began and died of hyperthermia and myopathy after a dead calf was extracted. This calf had a severe malpresentation with 90-degree rotation and head flexion.³

Four of the 14 complex cases were successfully managed by using a restraint chute to control the dam. One was a limb flexion, in which intervention was initiated after 2 h of hard labor and both dam and calf survived. The second case was a dead calf, with the head and one limb flexed, which was removed by fetotomy after intervening 1 h into labor, and the dam survived. The third case was another severe dystocia with head and neck flexion. Intervention occurred after 16 h of labor and a fetotomy was successful in sparing the dam. Two of the three dams were sedated with xylazine while the third was not given any drugs. The fourth case involved a primiparous dam with a normal presentation. Two hours into labor, when there was no progress, oxytocin was given and repeated twice in the next hour. Standing sedation was initiated after 3 h of labor, using xylazine, azaperone and detomidine, with the dam in a restraint chute. After 3 h of unsuccessful attempts to pull the calf, the dam became recumbent in the chute and a stillborn calf was extracted. The dam stood up 2 h later.

The final two complex cases were fatal to the dams before intervention could begin. One dam was found down in the morning with its rear legs splayed and the feet of the fetus projecting from the vulva. The head of the dead fetus was flexed and the dam died before a fetotomy could be performed. The second case presented as a 90-degree rotation of the fetus which delivered to the hips before progress ceased. The dam was unapproachable in the exhibit and fell on slick ground while attempting to swing the fetus to dislodge it. The dam’s rear legs splayed, resulting in a severe pelvic fracture, and both dam and calf died before intervention could be attempted.

Intermediate Cases

These cases were managed by either no restraint of the dam or by brief chemical restraint and required no direct obstetrical exam or corrective fetal manipulation. There was moderate risk to the dam from fatigue or chemical restraint. Five cases of dystocia fitting this description were reported. Three of these were posterior presentations and the other two were normal presentations.

The three posterior presentation cases included two dams that labored for 4 and 6 h before becoming fatigued and were safely approached to pull the calves without restraint and without fetal correction. Both sets of dams and calves survived. The third case occurred in a tractable dam and was the only twinning reported in the survey. After more than 6 h of unproductive labor a small calf (about 30 kg) was easily extracted by ropes secured to the feet. Soon thereafter a second set of hind hooves appeared and a twin of the same size was pulled. Apparently, the fetuses had simultaneously wedged in the pelvic canal.

One case with anterior presentation was described as a shoulder lock. After 6 h of labor the calf appeared dead, with an edematous head and neck protruding from the vulva. The head was lassoed and the calf was easily extracted when the dam stepped forward. The final case of normal presentation was in a dam which was recumbent from fatigue and apparent uterine inertia after 5 h of labor. A live calf was easily pulled and survived but the dam remained recumbent and died during the night.

Uncomplicated Cases

These uncomplicated dystocias were managed by either no restraint of the dam or by brief chute restraint. They involved no obstetrical exam or corrective fetal manipulation and there was minimal risk to the dam. Many were resolved by simple traction on the fetus and, in the remainder, birth was without physical intervention.

Fifteen cases of dystocia fitting this description were reported and 11 were anterior presentations. One dam was observed to have three feet and the head of a calf visible at the vulva after 3.5 h of labor. An hour later the dam began running around the exhibit and eventually passed a 34-kg stillborn calf without assistance. Another dam, this one primiparous, gave birth after a 7-h labor. At some point it was given an injection of oxytocin, which had an undetermined effect. Another three of the 11 cases in this series involved two different dams and were resolved by manual extraction of the calf relatively early in labor (2–4 h) with no restraint of the dam. Early intervention was elected because of a previous stillbirth in each dam which was thought to have resulted from waiting too long. All three calves were pulled with relative ease and survived. The six remaining cases were resolved by extracting the calves with simple traction after 4–6.5 h of labor. Three of the calves survived and three were stillborn. Two of the dams were placed in a restraint chute for the procedure and four were worked without restraint. Novel methods were used in some cases to remain at a safe distance from the dam, such as threading a rope through a section of hollow rigid tubing, leaving a loop at the end to secure the fetal extremities.

The remaining four uncomplicated cases were posterior presentations. Three of the four dams gave birth to surviving calves without intervention (one after 8 h of labor, one after 6 h of labor and the third had no data on the length of labor). The fourth dam was placed in a restraint chute 2 h into labor and a live calf was easily pulled, which the mother subsequently reared.

ABP Cases

Four dystocias occurred between two reticulated giraffe dams. One case was in a wild-caught animal and the other three were from one of its offspring. The wild-caught dam had five consecutive normal presentation births over a 9-yr period with no problems and all were delivered within 2–4 h of labor. The sixth birth, a complex case of posterior presentation, presented with two upside-down hoofs protruding from the vulva when the keeper arrived in the morning. No further progress occurred over the next 3.5 h, with very hard straining during the last hour. Oxytocin (140 mg), given when the hard straining subsided, had no noticeable effect then, or when later repeated. Chemical immobilization began 6.5 h after the labor was first seen, since there had been no progress in the delivery. The dam was confined by a crowding gate and then given xylazine (200 mg) followed by etorphine (4 mg). Obstetrical exam revealed a second-degree vaginal tear and extensive contusions surrounding the urethral orifice, extending anteriorly for 18–20 cm. Three persons pulling obstetrical chains on the calf’s hind legs could not induce movement. Stronger force applied over 10 min by a modified calf puller successfully dislodged the hip lock and a 75-kg stillborn calf was delivered. The placenta separated by gentle traction over 20 min and the vaginal tear was closed using absorbable suture. The dam stood up 2 min after reversal of the etorphine. A complication occurred when the next calf was born 20 mo later. The initially healthy calf from a normal delivery died of hemolytic anemia at 7 days of age. The diagnosis was neonatal isoerythrolysis resulting from sensitization of the dam via the vaginal tear of the previous dystocia.

The other three dystocia cases were from an offspring of the previous dam. This animal had three posterior presentation deliveries out of five births in a 6.5-yr period during which it was bred back to its father. It later had three normal births and one abortion when bred to an unrelated male. The first dystocia, an uncomplicated case, had 6.5 h of nonproductive labor with approximately 30 cm of the fetal extremities showing. Oxytocin (140 mg) was given, strong contractions were induced and the fetus progressed about 50 cm. Another oxytocin dose (100 mg) given 1 h later induced strong contractions followed by birth of a stillborn calf 15 min later. The second dystocia was of intermediate complexity in that chemical restraint was needed. About 30 cm of fetal extremity protruded from the dam’s vulva after several hours of labor. Oxytocin (140 mg) induced about 30 cm of further progression before progress stopped. Since the dam could not be safely approached, it was then given xylazine (200 mg) followed by etorphine (4 mg), and the calf was quickly extracted by ropes placed on the hind legs just prior to the dam’s recumbency. The dam quickly regained its feet after reversal of the immobilizing drugs, but the calf died soon after the delivery. Nearly identical circumstances occurred with the third dystocia, although intervention started after 3.5 h of labor. A lower dose of etorphine (2 mg) provided brief standing chemical restraint sufficient to pull a 75-kg live calf. Recovery was rapid after reversal of the etorphine and xylazine. This calf later required euthanasia for an unrelated problem.

Prolonged Second Stage of Parturition

Observations of a prolonged second stage of parturition (extending 4–6 h or longer) in births not considered dystocias were reported from six other institutions and in one case at ABP. Two cases which were closely observed were seen to have two phases to the second stage of parturition. The first phase was a resting or nonproductive labor with mild to moderate contractions, usually of less than 1 min duration occurring at 10–15 min intervals or longer. This lasted 5 h in an ABP case and nearly 7 h in the other case. The dams remained calm, alert and exhibited no distress, even eating or chewing cud intermittently while the feet of the calf remained protruding from the vulva. Then the second phase (hard labor) began, characterized by strong braced contractions lasting 1–3 min and occurring at more frequent intervals (3–10 min). Birth occurred approximately 10 min after the head and shoulders were presented in the ABP case or once the hips were presented in the other case, which was a posterior presentation. This followed after about 60 min of hard labor in both cases. Three other live births, also not reported as dystocias, had labors of 6.5, 7.5 and 8 h respectively with normal presentations of the fetus.

Discussion

Dystocia is defined as any abnormality in the progress of parturition, including the stages of cervical dilation, fetal expulsion and passage of fetal membranes, but it is more commonly understood to reflect a difficult labor during the phase of fetal expulsion.^6,7 Although retained placenta is technically a dystocia, the survey was intended to more narrowly identify cases of abnormal second stage labor in which there was veterinary involvement. A posterior presentation birth in a ruminant is by its nature a fetal malpresentation even if the birth proceeds without assistance, thus all of these cases were included as dystocias. Observations on delayed second stage parturition were not specifically sought from the survey but were derived from the responses and correlated with APB experience.

The cases of dystocia reported here varied from minor self-correcting problems to life-threatening dystocias, including eight fatalities among the dams. The data suggest that some type of abnormality of parturition occurred in approximately 3% (38/1254) of captive giraffe births from ISIS-registered institutions in North America in the past 20 yr. About 1% of births (15/1254) were complex dystocias requiring a corrective obstetrical procedure with the dam under full restraint. Within these 15 complex cases, five of nine dams managed by chemical immobilization died, while all four dams managed in a restraint chute survived. Two other dams died prior to intervention. Calf survival from the complex dystocia cases was 2 of 15 (1 from an immobilized dam and 1 from a chute restrained dam). Compared to the complex cases, six of seven dams survived from the intermediate category, while three of eight calves lived. All 16 dams survived that had uncomplicated dystocia cases while 11 of the 16 calves survived.

The high incidence of posterior presentation at ABP probably represented individual predisposition to dystocia since three cases were from the same dam and the fourth was from its mother. Factors which may influence the occurrence of dystocia (such as inbreeding depression, nutrition, subclinical disease or management factors) could not be established from the data evaluated, although genetic predisposition was possible in the ABP cases.

A delay in the second stage of labor may be explained by the giraffe’s ability to postpone the birth process for many hours even after second stage labor has begun and the feet of the calf have appeared.⁴ This apparent adaptation to avoid predators in the wild may account for some of the labors of 4–6 h or longer in captivity in which live births occur without assistance to the dam. Births monitored by human presence may stimulate a protective response in some dams⁴ and this was mentioned by one respondent as the cause of delay in a birth. This assessment of extended labor is based on limited observations, yet best fits our experience and the data collected. One birth reported was a posterior presentation with a long resting period of 7 h. Then 1 h of hard labor produced a live calf without intervention. Another similar posterior presentation case delivered successfully after 6 h. ABP experienced a labor of more than 6 h with a 5-h resting phase which produced a healthy calf. Differentiating a prolonged second stage labor from a true dystocia involving malpresentation or malposition will hopefully be enhanced from the information given here. Caution is warranted in assessing all cases, particularly if a restraint chute is not available while intervention is considered.

Acknowledgments

The authors wish to thank all of the institutions and individuals who responded to the initial questionnaire. The complete list of respondents is regrettably too long to include. We especially acknowledge those institutions and individuals who provided data on dystocias (institutions are abbreviated and since the information is historical, individuals listed may not reflect their current place of employment): Atlanta (M. Crane), Baltimore (M. Bush), Baton Rouge (G. Pirie), St. Louis (B. Boever), Buffalo (A. Prowten), Caldwell (K. Reese), Calgary (B. Cooper), Chaffee (S. Lynch), Cheyenne Mtn (D. Garrell, B. Cook), Cincinnati (K. Cameron), Detroit (D. Agnew), Ft. Wayne (K. Casserly), Gladys Porter (M. Willette-Frahm), Henry Doorly (D. Armstrong), Honolulu (B. Okimoto), Houston (J. Flanagan), Jacksonville (D. Page), Brookfield (J. Joslin), Kansas City (K. Suedmeyer), Lion Country (P. Wollenman, B. Lift), Los Angeles (G. Kuehn), Marine World (L. Gage), Pittsburgh (D. Neiffer), Reid Park (M. Flint), Riverbanks (N. Lamberski), and San Diego WAP (P. Ensley).

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