The prevention of breeding in animals using GnRH analogues has been the object of research over many years. Recently, a new
drug delivery formulation was developed which enabled the development of products that could be commercialised for veterinary
use. The formulation has now been approved in certain countries for use in male dogs, and applications are being expanded to cover
repeat usage, extended duration, use in females, other indications and other animal species.With respect to repeat usage, dogs have
been re-implanted for four consecutive doses and monitored until they returned to normal steroidogenesis. All dogs returned to
normal steroidogenesis following cessation of treatment. In females, it was previously shown that implanted bitches with
progesterone