Use of a deslorelin implant for influencing sex hormones and male behaviour in a stallion - Case report.

This case report describes the use of a subcutaneously applied 4.7-mg deslorelin acetate implant in a three-year-old Arabian crossbred stallion showing unwanted strong male behaviour. Following deslorelin acetate implantation the stallion showed a short transitional increase in male behaviour. A 'gelding-like' behaviour was noted 15 days (D15) after treatment. The horse was surgically castrated at the owners request at D52 after treatment. Serum testosterone, oestradiol-17β and oestrone sulphate values decreased after deslorelin acetate implantation, but serum LH and FSH levels remained unchanged. Histopathological analysis of both testes and sperm analysis revealed a reduced spermatogenesis at D52. The testicular volume decreased after treatment. The use of a subcutaneously applied deslorelin acetate implant might be a promising tool to change the behaviour of aggressive stallions.