Operative Vaginal Birth of a Critically Endangered Gorilla With Forceps Assistance.

BACKGROUND: An obstetrician on standby assessed an 18-year-old primiparous captive gorilla with a term singleton fetus with a protracted labor course. CASE: After it was determined that an arrest of descent had occurred, a viable, 2,280 g male neonate was delivered through an operative vaginal birth with forceps assistance without major complications. CONCLUSION: Given the numerous anatomic and biochemical similarities of humans and other great apes, it is possible that the high maternal mortality and stillbirth rates of gorillas could be reduced by using the same principles of obstetric management in a multidisciplinary fashion.

Assessment of calving progress and reference times for obstetric intervention during dystocia in Holstein dairy cows.

The objectives of this observational study were (1) to assess the time from the appearance of the amniotic sac (AS) or feet outside the vulva to birth in Holstein cows (primiparous and multiparous) with (dystocia) or without assistance (eutocia) at calving, and (2) to estimate reference times to be used as guidelines for obstetric intervention in Holstein cows that need assistance during difficult births. Cows (n=92) from 1 commercial dairy operation were used in this study. Periparturient dairy cows (primiparous, n=58; multiparous, n=34) were placed in a maternity pen and constantly monitored until birth. The calving ease of cows, time from AS or feet appearance to birth, calving progress from a subset of 15 cows (frequency and duration of abdominal contractions during labor), calf birth weight, calf sex, and stillbirths (born dead or died within 24h after birth) were recorded. The reference times for obstetric intervention during dystocia were estimated based on values from unassisted births (normal). The normal range of times from the appearance of AS or feet outside the vulva to birth was estimated based on the mean+2 standard deviations (SD) of unassisted births. According to farm protocol, assistance was provided to cows without calving progress 80 min after AS appearance or earlier (e.g., to correct malpositions). Cows with dystocic births had a longer time from AS appearance to birth and increased incidence of stillbirth compared with cows with eutocic calvings. After the appearance of the AS, calving progress was evident every 15 min for eutocic births. The estimated reference times (mean+2 SD) from AS appearance to birth were 69.7 min and from feet appearance to birth were 64.6 min for eutocic births. Findings from this study suggested that calving personnel should start assisting cows 70 min after AS appearance (or 65 min after feet appearance) outside the vulva. The time spent in labor (straining) combined with the time from the appearance of the AS or feet to birth, and the assessment of calving progress (as described for eutocic births) should be used as guidelines for obstetric intervention during difficult births under field conditions. These reference times should be interpreted in combination with adequate obstetrical knowledge and examination.

Extraction methods in bovine obstetrics: comparison of the demanded energy and importance of calf and traction method in the variance of force and energy.

In a previous study we could demonstrate that in terms of the required forces alternate traction is preferable to simultaneous traction for the obstetrical delivery of calves. The aims of this study were to examine the required energies for delivery of calves and to compare the effects of the factors of calf and traction method on the forces and energies required for the delivery. In a biomechanical in vitro model 12 stillborn Holstein-Friesian calves were pulled through the pelvic specimen of a cow at a controlled speed using two electric motors. Traction was applied simultaneously (ST) to both legs or alternately (AT) to one leg at a time to advance it 10 cm (AT 10) or 5 cm (AT5). Energies on each limb were measured digitally using load cells. The lowest energy for the entrance of the elbows in the pelvis was necessary using AT10 (19.9 ± 7.2 kJ, P < 0.05). In contrast, for the entrance of the chest, AT10 (104.9 ± 24.7 kJ) demanded 9% (P < 0.01) and 16% (P < 0.001) more energy than AT5 (96.7 ± 21.0 kJ) and ST (90.5 ± 24.9 kJ), respectively. Simultaneous traction tended to be better than AT5 (P = 0.09). Variance component estimates revealed that the factor calf contributed the main effect to the emerging forces and required energy. The traction method was responsible for up to 13% of the variance in most of the cases, but it accounted for 42% of the variance regarding the forces on the lower limb as the chest entered the pelvis. Based on these findings, the decision of the clinician whether or not to perform a manual traction should depend mainly on the calf. However, when such a decision has been made, alternate limb traction, 10 cm at a time, should be used until both elbows have entered the pelvis and a simultaneous traction should then be applied to complete extraction of the chest.

Extraction forces in bovine obstetrics: an in vitro study investigating alternate and simultaneous traction modes.

Whether extraction of a calf in longitudinal anterior presentation should be carried out by simultaneous or alternate traction on the forelimbs remains controversial. Because most recommendations are based on empirical observations rather than on scientific studies, the aim of this study was to develop an in vitro model to objectively compare the forces occurring during alternate and simultaneous traction. In a biomechanical in vitro model, 12 dead Holstein-Friesian (Bos taurus) calves were pulled through the prepared pelvic specimen of a cow at a controlled speed using two electric motors. Traction was applied simultaneously (ST) to both legs or alternately (AT) to one leg at a time to advance the calf 5 cm (AT 5) or 10 cm (AT 10). Forces on each limb were measured digitally using load cells. In all cases, two peaks of maximum force occurred during the extraction of the cranial part of the body. The first peak was observed when the elbows were pulled into the pelvis, and the second peak occurred when the chest emerged from the pelvis. Up to and including entry of the elbows into the pelvis, the maximum force on a single limb (341+/-106 N) was lowest (P<0.01) using AT10. The maximum traction forces acting on a single limb using AT5 (411+/-86 N) and ST (431+/-127 N) did not differ (P>0.05). During extraction of the thorax, the maximum force acting on a single limb was lower (P<0.0001) using ST (352+/-98 N) compared with AT5 (432+/-79 N) and AT10 (547+/-115 N). Based on these findings, alternate-limb traction, 10 cm at a time, should be used until both elbows have entered the pelvis. Simultaneous traction should then be applied to both forelimbs to complete extraction of the chest.

Medical management of canine and feline dystocia.

When dystocia is diagnosed in the bitch or queen, two forms of treatment exist: medical or surgical therapy. Medical management of dystocia has the advantage of aiding completion of the parturition process without surgery or anesthesia. However, since not all cases of dystocia can be managed medically, educated and careful decision making is required prior to instituting medical management in cases of dystocia. Improper medical treatment, especially when surgical management is clinically indicated, can result in compromise and even death of the dam and fetuses. This paper focuses on the decision making necessary prior to instituting medical management for cases of dystocia in both bitches and queens, and describes available therapeutics.

[Electronic quantification of traction force during use of a mechanical calving aid in bovine parturition]. / Elektronische Zugkraftquantifizierung bei Anwendung des mechanischen Geburtshelfers in der Rindergeburt.

In this study, a specially developed computer-controlled system was used to obtain a continuous measurement of the forces that arise when using a mechanical calving aid. By this means, potentiograms for twenty-four births in cows using a tractive device were obtained (fourteen primiparae with an average age of twenty-eight months; ten pluriparae with an average age of fifty-four months; breeds: thirteen RB, eleven SB). A modern mechanical calving device with a locking mechanism was used as an aid in the extraction process. In births with use of light tractive force (approx. 50 kp), extraction took between 41 and +/- 21 seconds. Moderately heavy tractive force (approx. 80-100 kp) was applied in extractions taking 86 to +/- 22 seconds, whereas heavy tractive force (etwa 100-120 kp) was used in extractions lasting between 268 and +/- 117 seconds. The highest levels measured for brief applications of force were between 130 and 140 kp. Single strains of up to 150 kp were reached. Injuries in the soft birth canal were ascertained in 29.2% of the births. Such injuries were discerned more often in primiparae than in the pluriparae. The lacerations were merely superficial and caused no further after-effects. There were no limb injuries in the calves. For the use of mechanical calving aids the use of chains with exact markings should ensure that the limbs are fixated at equal lengths. Furthermore, every device should be equipped with a locking mechanism (150 kp) to prevent the use of too much force. This also prevents misjudgment of the birth situation concerning fetus size and the dimensions of the mother cow's pelvis.

A case report on the use of guaifenesin-ketamine-xylazine anesthesia for equine dystocia.

In 4 mares suffering from dystocia, general anesthesia was induced with xylazine (1.1 mg/kg, IV) and ketamine (2.2 mg/kg, IV) and maintained with continuous intravenous infusion of ketamine (2 mg/ml), xylazine (0.5 mg/ml) and guaifenesin (50 mg/ml) in 1 L of 5% dextrose. The duration of the procedure of these mares were 40, 45, 180, and 35 minutes, respectively. For procedures required more than 1 hour (Mare 3), the dose of ketamine and xylazine in the mixture was reduced to 1 mg/ml and 0.25 mg/ml, respectively. Average infusion rate of the mixture used to maintain anesthesia for each mare was 2.5, 2.67, 2.28, and 2.21 ml/kg/hr. Recovery to standing occurred at 55, 75, and 180 minutes after termination of infusion for mares 1, 2, and 3, respectively. Xylazine reversal agent, tolazoline (2.2 mg/kg), was given to mare 1 to hasten the recovery; the mare stood within 30 minutes after tolazoline administration. Continuous infusion of guaifenesin-ketamine-xylazine can be an alternative anesthetic technique for prolonged obstetrical procedures under field conditions when suitable anesthetic equipment is not available. If recovery to standing is extended over 30 to 40 minutes, yohimbine or tolazoline can be administered to hasten recovery.

Abnormal bovine parturition. Obstetrics and fetotomy.

The veterinarian is in a unique position to assist and improve the profitability of producers by educating clients on proper intervention and delivery techniques. This paper describes some procedures for intervention, evaluation, and management of dystocia by mutation, forced extraction, and fetotomy. In addition, a brief summary of the factors influencing dystocia is presented. When these techniques are used properly, losses due to dystocia are minimized.

Iatrogenic fractures of ribs and vertebrae during delivery in perinatally dying calves: 235 cases (1978-1988).

To determine the pathogenesis of vertebral fractures in calves during the perinatal period, a retrospective study was done to determine the relationships between clinical factors at dystocia and the findings during necropsy of 235 perinatally dying calves. It was concluded that excessive traction is the most important cause of rib and vertebral fractures in the calf during dystocia. Vertebral fractures in perinatally dying calves may not be simply judged as a sign of asphyxia. The occurrence of vertebral fractures is highly correlated with the type of delivery and the force of traction. The veterinarian as well as the type of calf also are influencing factors. More perinatally dying calves were delivered after hips were locked, when extraction had been forced, or through induction of trauma when the head of the calf had the pelvic canal during the first obstetric examination. Consequently, fetal position at delivery may predispose calves to risky extractions and to the risk of perinatal death secondary to trauma. In light calves, significantly more vertebral fractures occurred during extractions than in other calves. Therefore, the veterinarian should accurately estimate the birth weight of the calf and the force of traction that should be applied.

Effects of dystocia on postpartum adrenocortical function in dairy cows.

Postpartum adrenocortical responses to adrenocorticotropic hormone in cows after normal (n = 10) and difficult (n = 52) parturition were investigated. The post-partum adrenocortical function of cows was affected by type of parturition (spontaneous parturition, forced extraction of fetus, caesarean section calving with or without attempted forced extraction, and total fetotomy) and day after calving (d 1, 4, and 8; d 0 = day of parturition). Cows after normal calving did not show enhanced or depressed adrenocortical function postpartum. Adrenocortical function was enhanced, compared with cows calving normally, for cows with dystocia that had a caesarean section after forced extraction was attempted and in cows in which calves were already dead and total fetotomy was performed. Cows with dystocia assisted with forced extraction by one to two people and cows that had caesarean sections without forced extraction did not show higher plasma glucocorticoid concentrations before or after adrenocorticotropic hormone administration than did cows with normal calving. Results indicate that dystocia requiring caesarean section following unsuccessful extraction or total fetotomy enhanced postpartum adrenocortical function in cows.

[Delivery-induced fracture of the spine in a newborn calf]. / Geburtsbedingte Wirbelsäulenfraktur bei einem neugeborenen Kalb.

The case of a 3 days old calf taken to the local animal hospital with a complete fracture of the vertebral column at the transitory point between thoracic and lumbar spine is reported. The fracture could be attributed to the wrong use of a mechanical fetal extractor, which is a common mistake when using it for forced extraction.

[The Munich obstetric instruments for cattle. Use during the birth of calves in VEL]. / Das Münchener Geburtshilfe-Besteck für Rinder. Einsatz bei der Geburt des Kalbes in VEL.

The consequent use of the Munich obstetrics instruments can lower the dystochia rate of cows. Based upon the measured traction energy, it is possible to give an objective prognosis of the further process of parturition. By the aid of the traction energy, measured during one labour, the decision to the C. section at the time can get easier. Beside the better survival changes of the calf, injuries of the cow, happened during the delivery, will be extensively avoidable.

Gnotobiotic pigs-derivation and rearing.

The procurement, rearing, nutrition and microbiological monitoring of gnotobiotic pigs and a method for conditioning of primary, colostrum-deprived, specific pathogen free pigs is described. As compared to the established hysterectomy and closed hysterotomy methods for the derivation of gnotobiotic piglets an alternative approach, open caesarian section with the sow maintained under general halothane-nitrous oxide anaesthesia and the introduction of each fetus into the sterile isolator via a liquid germicidal trap, was found to be more efficient and equally successful in providing viable and microbiologically sterile piglets. Two sterile commercially available milk diets, a special formula for orphan animals and condensed cow's milk, when the latter was supplemented with injectable vitamin E, selenium and iron, proved adequate for satisfactory health of the animals. Two types of pelleted starter rations, sterilized by 4.5 megarads of gamma irradiation, provided adequately for the nutritional needs of older gnotobiotic pigs. Results of microbiological monitoring indicated that the surgical and rearing methods employed were capable of preventing contamination of the animals with bacteria, mycoplasma, yeasts, molds, protozoa and helminths but probably could not exclude occasional vertically transmitted viral infections. Exposure of the animals for four weeks to selected strains of lactobacilli, fecal streptococci and Escherichia coli did not result in visible disease while they were maintained in isolators and conditioned them for transfer into a conventional microbial environment.

Quantification of obstetric traction.

Measurements of factors involved in the degree of traction exerted during obstetric cases were carried out. Bovine material force was approximately 150 lbs. Maximum manual effort would be approximately four times this and mechanical traction would be at least 50 per cent higher again. A workable maternal fetal ratio was established for use in cases of fetal oversize. Possible quantification of other factors is also discussed.