ASSESSING THE EFFICACY OF DESLORELIN ACETATE IMPLANTS (SUPRELORIN) IN ALTERNATIVE PLACEMENT SITES

Hormonal contraception is being increasingly used to manage captive animals in zoological collections. Many of the animals placed on contraception are of genetic importance within captive breeding programs; therefore, it is imperative that the application of contraceptive products minimize potential side effects and facilitate a return to fertility if required. Deslorelin acetate implants (Suprelorin®) are one example of a hormonal contraceptive that is frequently used in captivity as they are easy to use and effective in most species. It is hypothesized that removing implants may hasten reversal of contraception treatment; therefore, placement in a location where they can easily be recovered is advocated. In this report, the efficacy and safety of Suprelorin implants placed in their recommended site between the scapulae is compared with alternative placement sites where implants can more easily be located for removal. Using the European Association of Zoos and Aquariums (EAZA) Group on Zoo Animal Contraception (EGZAC) Contraception Database, rates of success, failure, and reversal in 561 records of Suprelorin use in European collections are compared. Of these, 357 have information relating to the location of implant placement. When correctly applied, rates of efficacy were high (>99%) irrespective of placement site. Rates of reversal were 33.3% higher in alternative placement sites, although in most cases it is unknown whether implants were removed or not. In conclusion, the placement of Suprelorin implants in alternative sites does not negatively affect the efficacy, facilitating at the same time implant removal, minimizing potential side effects, and reducing reversal time, allowing for effective use in captive conservation breeding programs.