Retrospective Evaluation of Deslorelin Acetate Implant Use in Several Captive Crane Species at One Facility

In captive cranes, chronic reproductive activity, aggression, and feather destructive behaviors are observed, and deslorelin implants have been used at the International Crane Foundation (ICF) to attempt to suppress gonadal hormone production. These sustained-release gonadotropin-releasing hormone agonist implants are generally effective in suppressing gonadal activity in mammals for 12-24 mon. However, in birds, the efficacy is substantially less, with greater variation in response and generally a much shorter duration of effect served. For this retrospective study, the medical record database of ICF was searched for deslorelin use in cranes. Thirteen individuals having received a total of 67 implants were identified for inclusion in this retrospective study. Seven species were represented. Cranes received implants to either stop or slow egg production (n = 56 treatments) or improve behaviors such as aggression and feather destructive behavior (n = 11 treatments). There were varied responses, with some individuals continuing to lay eggs an average of 30 d after treatment and others ceasing to lay eggs for the rest of the year. There were also variations in response between years within the same individuals. Aggression improved following treatment (n = 2 treatments total, n = 2 individuals). There was minimal response in relation to feather destructive behavior (n = 9 treatments total, n = 3 individuals).