The past, present and future of hormonal contraceptive use in managed captive female tiger populations with a focus on the current use of deslorelin acetate

Abstract

Tigers (Panthera tigris spp.) are endangered in the wild; ensuring sustainable insurance populations requires careful planning within zoological collections. In captive situations, contraceptives are often used to control breeding and ensure genetically viable populations that contain manageable numbers of animals; reversible contraceptives are ideal because they offer flexibility for breeding management. Historically, synthetic progestins, such as melengestrol acetate implants, were used in female tigers, but these are associated with an increased risk of reproductive pathology and subsequent infertility. Recent management advice to ex-situ collections has been to transition to the use of gonadotropin-releasing hormone agonists, such as deslorelin acetate implants, which do not appear to have a similar risk of reproductive pathology but are associated with highly variable reversal times in exotic felids. Using data from 917 contraceptive records in female tigers captured by the Association of Zoos and Aquariums Reproductive Management Center and the European Association of Zoos and Aquaria Reproductive Management Group's joint Contraception Database and from supplementary surveys, this study reviews the changing use of contraceptives in captive female tigers.The aim was to describe the historical and current use of contraceptives and provide a comprehensive assessment on the use of deslorelin implants, including data on product protocols, efficacy, pathology, and reversibility. This study determined that current dose, frequency, reversibility, and anatomical placement sites of deslorelin implants are highly variable, indicating that specific, readily available, unified, evidence-based recommendations on the use of deslorelin would be useful for future contraceptive use in managed tiger populations.

Biological and Management-Related Predictors of Reproductive Success in North American Ex Situ Asian Small-Clawed Otters (Aonyx cinereus)

“…The rate of reversal post-deslorelin treatment observed among female ASCOs in this study (53.3%, N = 8/15) is comparable to that reported for tigers (55.6%, N = 10/18) [36] and across various other taxa (62.5%, N = 10/16) [19]. Traditionally, deslorelin implants are placed between the scapulae.…”

“…Our analyses also indicate that the time to reversal post-implant treatment was faster among females who had their implants removed. In contrast to this study, there was no association found between implant removal and reversal in tigers [36]. Cowl et al, 2018, found that placing deslorelin in alternative sites, such as the base of the ear or forelimb, had equivalent contraceptive efficacy and a higher rate of reversal compared with the traditional placement site (83.3% reversal rate vs. 50% reversal rate, respectively) [19].…”

Wound Retractor Laparoscopic Port System for Laparoscopic Ovariectomy in Panthera leo

“…Big felids cared for in many zoos and sanctuary facilities breed so effectively that contraceptive methods are used to keep the population at a healthy size. Reproduction can be avoided by separating the sexes or through permanent sterilization [1], in addition to reversible contraception and gonadotropin-releasing hormone (GnRH) agonists [2][3][4][5],…”

“…progestins implants [6], and vaccines [7]. Although reversible contraception is desirable since it permits natural social groupings to be preserved while maintaining the population's genetic health [2], surgical contraception has been utilized in animals with various pathologies and medical disorders and in animals that should not be bred [1]. Furthermore, for individuals who are genetically well represented or for whom reproduction might entail potential health risks, permanent sterilization may be considered.…”