Normal birth process

This chapter is based on the EAZA Guidelines for the reproduction-related management of female elephants.

Taken care at the birth process means that the pregnancy has been confirmed. More detailed information is provided in the chapter: pregnancy confirmation.

After a pregnancy period of 87-95 weeks (610- 670 days, 20-22 months), parturition is sometimes announced by subtile changes in the behaviour of the elephant. Twentyfour hours observation including the use of a (time-lapse) video recorder starting in week 85 may add to information about relevant events prior to parturition: night pacing, kneeling down, climbing, short periods of separation from the group, beating the vulva with the tail, frequent production of small-sized feces and small quantities of urine, loss of mucous plug, playing with mucous plug, rupture of the allantois sac, labour waves.

Preceding any recommendation in this chapter, the following remarks need to be made:

  1. It is a myth to think that a multiparous elephant does not need to be monitored and assisted during parturition according to this protocol. Too many calves have been born dead or very weak because of the fact that parturition had started unnoticed and stopped unnoticed. In our view, this protocol should be followed in ALL cases of elephant parturition as much as the elephant management allows.

  2. It is a also myth that oxytocin is a harmless drug to be used in elephant parturitions. In at least 3 cases the administration of oxytocin has been associated with the occurrence of an uterus rupture because of insufficient cervix dilatation. It should never be used without ultrasonographic examination of the cervix uteri. The visible presence of the allantois sac as a subcutaneous bulging mass under the tail is not a guarantee for a sufficiently dilated cervix.

  3. Many elephants, including very experienced multiparous elephants may just stop the parturition process, often unnoticed. Hypocalcemia is one of the main causes for this phenomenon to happen.This will compromise the health of the calf. Don’t relay only on what you see from the outside! For a proper judgment about the presence of labor activities or the progress of parturition, your professional judgment should be based on the results of progesterone tests and ultrasonographic examinations.

  4. If you do not believe in the above mentioned statements, you may find yourself confronted with a dead elephant calf or a dead elephant mother or both. So, discuss this item with your staff and make your decision before you start breeding your elephants.

  5. If the management of elephants in your zoo does not allow blood sampling or ultrasonographic examinations, you must be aware of the risks associated with a silently interrupted birth process, no matter the reproductive experience of the animal involved. Safety for the personnel should never be challenged by unacceptable risks.

 

Predicting the time of parturition, measures and observations:

Daily blood sampling from week 89: every other a day progesterone assay, until week 91

(637 days). From week 91 (637 days): daily assays and as soon as progesterone starts to

decrease: sample twice daily.

Daily monitoring of progesterone is only possible if you have a nearby facility that runs these assays on a daily basis. Find out from your nearby hospital in the early stage of

pregnancy! Many veterinary labs do not have tests that are sensitive for levels of 

progesterone (P4) in elephants 1-3 days prior to delivery. Also check the availability during

the weekend.

 

NOTE: a decrease of progesterone to baseline level is not always occurring. A 23-yrs-old Asian elephant at the Rotterdam zoo (with a baseline progesterone level < 0.6 nmol/l) delivered a healthy calf while her progesterone remained above 0.65 nmol/l.

Progesterone plasma concentration during pregnancy. after a gradual decrease in the last months of gestation, progesterone drops to baseline level a few days before parturition.

Note that the absolute height of the progesterone concentration depends on the assay used! Different assays measure different metabolites = different levels!

Signs of an approaching parturition may include:

·Loss of mucous plug (not seen in many facilities)

·Pre-and post-parturition ventral edema may be noticed.

·Group members may react differently (vocalizations, restlessness)

·In most cases (75%) rupture of allantois sac and loss of allantois fluid (looks like urine) is seen within 2 hours prior to birth.

·The size of fecal balls may get smaller towards the end of pregnancy.

·Frequency of urination may increase around parturition, resulting in more “watery” consistency of the urine, resembling more like allantois fluid .

·Development of mammary gland and production of milk shortly before birth is often seen, however this may also occur in a much earlier stage of pregnancy . Milk accumulation can be visualized using transcutaneous ultrasonography several hours prior to parturition.

·Softening of the pelvic ligaments (due to estrogen surge) may result in slightly abnormal locomotion of the hind legs.

 

Parturition/Preparations for calving:

·Training and/or desensitizing of the pregnant elephant for veterinary intervention, like blood sampling, injections, IV-infusions, milking and rectal manipulations

·If possible, store some colostrum (freezer) or store plasma obtained from the dam in weeks prior to parturition.

·Have artificial milk available (Salvana GmbH, Germany; hand raising has been done at Emmen Zoo and Berlin Zoo)

·Check restraint chains and fixation points for the legs and one extra fixation point between the hind legs for pulling devices. Soft ropes for pulling the calf away if needed should be available. The use of a calf harness has been described.

·Check the stable and place bars where a calf could possibly escape. Block all possible escaping routes for the calf (not for staff!!).

·Take out all obstacles.

·Be prepared for closing the elephant house for the public (sign post, etc.)

·Make sure there is a good stock of commercial cat litter or saw dust to be used on a concrete floor as soon as the calf is born. This will absorb much of the allantois fluids and prevent the animals from slipping on the wet floor.

·2 or 3 pairs of keeper-gloves (soccer) to get a better grip on the wet, slippery calf when   needed

·Plastic hose pipe (with pump, if necessary) for rectal cleaning with lukewarm water

·3 birth-chains with proper handles (2 for the legs, 1 for trunk or tail); find a way to avoid back sliding when manual extraction (vaginal vestibulotomy) is required.

·Drugs to be kept in store:

·Ca-borogluconate for I.V. infusion

·Estradiol gel (EstroGel® 0.06%)

·Oxytocin

·Lidocain

·Xylazine, detomidine or medetomidine

·Butorphanol

·Azaperone

·Atipamezole

·Doxapram

·Oxygen

·(Betadine®-)iodine solution for navel disinfection (umbilical infection is a major cause of perinatal complications)

·Lubricant (many liters).  J-lube®, a concentrated lubrication powder, has proven to be very useful.

 

The normal calving process should take place within 2 hours after rupture of membranes (release of fetal fluids).

If the plasma progesterone level decreases to below base line concentration, this is a signal that calving should take place within 48 hours. Prolonged intervals have been reported (as long as 14 days) still resulting in the birth of a living calf, but it is very likely that this is due to a disturbance of the normal birth process that should be corrected before the health of the calf is jeopardized. There is one report of a parturition taking place without a complete drop to base line level.

 

The calving process is a natural process. Elephants should give birth in their own social environment, excluding any external disturbing factors (e.g. noisy building in the neighborhood, visits of unknown individuals, etc.). With a well trained animal, blood sampling and ultrasonographic examinations can be done while the animal is temporarily separated from the group. Immediately afterwards, the animal should return to its group. All efforts should be made to make sure that the calf is born in the group while the mother is NOT chained! This will stimulate the acceptance of the calf by the mother and group members and is an investment for future breeding successes for the entire elephant group. 

To determine the right moment when calving starts, 2 parameters are essential:

  - The progesterone blood level

  - The relaxation of the cervix, monitored by ultrasonographic examination.

 

Progesterone: the sensitivity of the equipment and the time needed to run the assay are the bottleneck for using the progesterone concentration as a reliable tool. Today many human hospitals use advanced equipment with a very low detection level that can provide results in less than 2 hours. Make sure that you have made arrangements with a lab long before you expect the parturition.

Ultrasonography: to use this technique as a reliable tool, it is indispensable for the veterinarian to gain experience long before the elephant birth is expected. This will enable the veterinarian to distinguish a normal cervix from the relaxed cervix (figure 4a + b) from the normal cervix. Preferably a 3.5 MHz probe should be used transrectally.

Longitudinal, transrectal ultrasonographic image of the vagina and the closed cervix of a pregnant elephant.

The same image as with the vagina and cervix indicated with white lines.             

Transversal, transrectal ultrasonographic vagina and cervix of a pregnant elephant.

Allantois sac with cloudy fetal fluid in the (partly) dilated cervix of an Asian elephant 12 hours prior to delivery (transverse section, white arrows: allantois sac, open arrow: pelvic bone)

The same image with the vagina and the closed cervix indicated by white lines. Note the folds in the cervix uteri.

Allantois sac with cloudy fetal fluid in the (partly) dilated cervix of an Asian elephant 12 hours prior to delivery (longitudinal section, white arrows: allantois sac, open arrow: pelvic bone)

During the last 2 weeks of gestation, the mucous that is present in the vagina during gestation

will be discharged gradually. This is a clear indication for a pending parturition.

Recognizable onset of parturition occurs normally within 24-48 hours after progesterone has dropped to below base-line level. In these guidelines the absence of visible signs of parturition in the same time frame is considered an abnormal condition; this status requires veterinary intervention. At this point 2 situations may occur: the parturition process has started but has been interrupted without or with spontaneous rupturing of the allantois sac.

Interpretation of findings and action to be taken

1. No rupture of allantois sac noticed

If the calf is not born by natural way 24 hours after blood progesterone has dropped to baseline level, rectal palpation and ultrasonographic examination of the cervix is highly recommended. This will demonstrate the rate of relaxation of the cervix, the presence of the allantois sac or parts of the fetus in the cervix or vagina and should be repeated at least every 8 hours.

 

A blood sample should be taken to measure the calcium level. If below 2.5 Mmol/l, calcium should be administered as an IV-infusion (NB: when given in an ear vein, it should be given strictly IV in order to avoid damage to the vein) or orally (suggestion: calcium syrup concentrate for human use, enveloped in the carton core of toilet paper, covered and sealed with fresh tamarind paste has worked well; most elephants will eat it, including the carton material). The effect of the calcium administration should be confirmed by rectal palpation (increase of contractibility of the uterus) and determination of the blood calcium level. Store an EDTA and heparine sample for herpes virus diagnostic purpose (both cells and plasma in freezer after separation).

 

Transrectal ultrasonographic examination at 48 hours:

A. No relaxation of the cervix at 48 hours: search for calf movements and nail position of the fetus (palpation and ultrasound) and blood flow in fetal vessels (ultrasound).

Transcutaneous ultrasonographic examination (both flanks have a small ”window” where visualization of fetal movements may be seen) may help to determine the status of the fetus.

Apply estrogens rectally. Good results have been obtained by the rectal and transdermal (perineum) application of an estradiol containing estrogen gel (Estrogel 0,06%, total dose 700-800 mg estradiol). The effect on the cervix dilatation should be monitored closely by transrectal ultrasonography! At this time, at least 1 hour after the local application of estradiol, rectal massage should be applied to test and stimulate the contractibility of the uterus. Technique: remove feces from rectum, flush out the rectum, use abundant lubrification, keep both gloved hands (NB: the rectal mucosa is vulnerable due to estrogens) with the fists joined in a firm grip and press with the wrists or the dorsal sides of the hands against the pelvic ring to stimulate the pelvic receptors until strong labor waves appear or at least 10 minutes. When labor waves occur, continue this massage for 3 hours (if needed change operator). Check regularly by means of ultrasound the condition of the cervix. If there is still no cervix relaxation, continue monitoring the viability of the calf. If no fetal parts can be detected, consider the presence of pseudopregnancy (ovarian tumor, dysfunction of the pituitary gland, etc.). The application of estradiol gel (total dose: 400-500 mg 17-β-estradiol) as described above may be repeated 3-4 hours after the first treatment if the cervix dilatation is still incomplete.

B. Partial or complete relaxation of the cervix at 48 hours or later as a result of  the situation described under 1A:

Apply rectal massage to test contractibility of the uterus. If limited or no reaction, the   administration of oxytocin is contra-indicated. In this case, the administration of calcium is recommended (even when blood calcium level is within normal ranges). After 2 hours the use of estradiol as described under 1.A is recommended.

Only if uterus contraction can be provoked by the rectal massage, the use of oxytocin may be considered using the following dosage: 25-50 IU oxytocin s.c. or i.m. (if needed use a blow dart).

Oxytocin should be used with care, as it may dramatically exhaust the contractibility of the uterus muscles as well as the general condition of the female. There might also be the risk of reduced blood circulation in the umbilical chord, due to the spasms in the myometrium.

Prostaglandine E (dinoproston) has been used on a few occasions for cervix dilatation (after the administration of estradiol) and to stimulate uterus contractions. As there is still limited knowledge of its efficacy after transrectal administration and the risk of stormy uterus contractions, it should only be used when any obstructions or abnormalities of the calf can be ruled out.

Depending on the progress obtained, rectal massage and the administration of oxytocin are the 2 major treatments to follow from this point. In between these treatment events, the animal should be exercised to relieve the pain and stimulate position changes of the calf and preferably it should be kept in the group. Only when the animal cannot be separated whenever required, the cow should be kept separated from the group, but with as much physical contact as possible. Oxytocin should be given in intervals of at least 2 hours for a maximum of 12-24 hours under the guidance of ultrasound to evaluate tAhe progress.

Continue this approach of treatment until parts of the calf have entered the pelvic cavity. If the efforts remain unrewarded and no access to fetal parts is possible, not much can be done. Continue monitoring the viability of the calf. If the calf has died, while the membranes are still intact, the risk of intoxication is limited, but immunosuppresion could be a complication for the cow. To date, no proper data are available.

The dosage of oxytocin may only be increased to 100 I.U. after parts of the calf have entered the pelvic area and progress is clearly observed. At this time, a bulge containing parts of the body under the tail of the dam should be visible. Progress of parturition must be monitored strictly at this stage. If this increased dose of oxytocin does not result in parturition a vaginal vestibulotomy should be performed soon to get better access to the calf. See next chapter.

 

Expulsion of the calf should follow soon after the bulge appears under the tail of the dam. The allantois sac usually ruptures during the (induced) passage through the pelvic canal.

One complication described at this stage, is reduced passage space as a result of edema in the urogenital canal resulting in a “catching effect” of the head and/or shoulder of the calf inside the soft part of the distal (vertical part) genital tract. Suffocation of the calf is a realistic complication. This condition has been observed several times in primiparous elephants of more advanced age. Elephants in this category should be prepared by the local application of J-Lube in the distal part of the vaginal vestibulum and massage of oestrogel/creme in the skin between anus and vulva. If this condition occurs, quick intervention is required by applying firm manual pressure from the outside on the calf in the sliding direction of the calf. Be aware of the risk of kicking by the mother.

2. Ruptured allantois sac

A significant event in the parturition process is the rupturing of the allantois sac, which – when intact - acts as a hydraulic dilatator for the cervix, a natural lubrication for the dam and a pressure protection for the calf.

NB: The amniotic sac that covers the body directly, usually remains intact during the expulsion of the calf and ruptures during the final passage through the birth canal and is actively removed by the dam.

NB: a chained dam, may not be in the position to remove these membranes, possibly resulting in suffocation of the calf.

 

Differentiation between urine and fetal fluids is extremely difficult; smell, creatinin test strips and possibly protein concentration could be helpful.

If no progress in parturition is observed, major complications should be considered, like a dead calf, malposition of the calf (which is often dead), oversized calf, malformation and twin pregnancy. Because of the urgency of this situation, the calf should be born within 2 hours after rupture of the allantois sac and loss of allantois fluid. If not so, veterinary intervention has to take place. Two situations may occur:

 

No fetal parts positioned in the pelvic area: treatment should aim on the urgent relaxation of the cervix. Calcium status should be determined and treated accordingly (see above). The further approach is according to 1A, however the situation is more critical for both the dam and the calf.  

 

Fetal parts have entered the pelvic area: Calcium status should be determined and treated accordingly (see above). Ultrasound is essential to determine which fetal parts have entered the birth canal, determine the position of the calf (visualization of the nails, posterior or anterior position, number of nails, trunk) and viability.

Malposition (e.g. only one leg in birth canal, no head while in anterior position) is an indication for vaginal vestibulotomy or fetotomy.  

If no abnormalities are found during ultrasound, 50-100 I.U. of oxytocin should be given i.v. or i.m. and rectal massage should be practiced. Birth should be completed within 1 hour.

Other drugs used

Uterine laxants have been used in elephants on rare occasions. There are some anecdotal reports about the use of denaverinehydrochloride (Sensiblex®, Veyx) at a dose of 0,04 – 0,05 mg/kg BW (i.m.). Isoxsuprinelactate (Duphaspasmin. Fort Dodge Animal Health,

6290AA Vaals, The Netherlands) was used in a fetotomy case at 0,15 mg/kg BM (i.m.). Carbetocine (Depotocin®, Veyx), a long acting oxytocine has been used in 3 occasions dosage (0,09 µg/kg BW) i.m.

Presentation of the calf

A study in 46 elephants demonstrated that the overall ratio between anterior and posterior presentation was 12:34. In dystochia cases the situation was quite different: 6:3. In normal birth procedures the ratio was 6: 29. Anterior presentation has a higher risk of dystochia than posterior presentation of the calf. (Ilic D. et al. 2021. The incidence of anterior and posterior presentation at birth in Asian (Elephas maximus) and African elephants (Loxodonta africana): A Review Study. Indian Journal of Animal Research.DOI: 10.18805/IJAR.B-1319)

It has been observed that the calf may rotate during the final phase of the expulsion, similar to what happens in horses and cattle (see video). This may be important in case of a dystocia, if the calf has remained in complete 'horizontal position' and a vaginal vestibulotomy is indicated.

Note that the calf has rotated during the final phase of the expulsion.

Transrectal massage:

Transrectal massage is a very effective method to stimulate uterine contractions if the uterus is prepared for it. Certain conditions (especially hypocalcemia) may impair the contractions. This should be solved first. Stimulation of the pelvic wall by rectal massage is known as the Ferguson reflex.

Transrectal massage of the pelvic wall is best performed by firmly pressing the closed fost against the roof and sides of the pelvic cavity and on the dorsal side of the vagina making the movements as shown in this video.

Post-partum care

Disinfection of the navel with Betadine® iodine is strongly recommended (if the mother allows its application).

The afterbirth usually comes off within 12 hours. There are a few reports on retained (parts of) placenta for several weeks, without major complications for the dam. Hygienic measures should be applied to reduce the infectious burden for the calf.

Be aware of the fact that a second calf can still be present in the dam. There are reports that second calves were born between several hours up to 3 months (the prevalence of twins in elephants is 1:3000).

 

The calf should drink (colostrum) as soon as possible, at least within 24 hours. If not, or when the calf makes a weak impression, the banked serum (or freshly taken serum) should be given to it orally. Try to find out the reason why the calf is not drinking successfully: e.g. too small, weak, painful mammary glands, malbehaviour of the dam.

 

If for any reason the mother is rejecting the calf, lactating herd member can take care of the calf. There is evidence that the mother takes over from this surrogate mother during the first 72 hours. If no lactating elephant is present in the herd, training for bottle feeding should start after 12 hours and continued for 72 hours. If the mother still rejects her calf, the best option for the calf is to move it to another herd with a lactating elephant. If introduction to this herd fails too, bottle feeding is the last option. To date very few bottle-raised elephants have reached the age of puberty.