REVIEW OF VETERINARY INTERVENTION IN REPRODUCTION OF CAPTIVE WESTERN LOWLAND GORILLAS () FROM 1996 TO 2016.

In order to gain an understanding of the frequency of veterinary intervention during the periparturient period of western lowland gorillas () in captivity between 1996 and 2016, a survey was sent to institutions associated with the Association of Zoos and Aquariums' Gorilla Species Survival Plan. A total of 193 births were reported during the survey period, from 51/53 institutions. There were six incidences of prolonged labor (longer than 6 hr; 3%), six cases of cesarean section (3%), and three incidences of veterinary intervention that did not involve a cesarean section (2%). Fifty-one gorilla neonates (26%) were assist-reared (required intervention lasting longer than 24 hr). Out of 51 attempts to reintroduce neonates to dams or surrogates, 42 were accepted (82%), while nine attempts (18%) were deemed failures. The age group with the highest rate of maternal or surrogate acceptance after reintroduction was between 6 and 12 mo of age. Compared to data from a 1981 survey, the percentage of assist-reared gorillas decreased from 64% to 26%. Results show that veterinary intervention in the periparturient period is low, and there is a high rate of acceptance of neonates by either the dam or a surrogate after intervention. Advances in captive husbandry and veterinary knowledge have led to a reduced risk of veterinary intervention during gorilla parturition; however, the long-term effects on behavioral development of the neonate should be considered before removal of the infant from the dam for any period of time.