The control of undesirable behaviour in male dogs using megestrol acetate

Megestrol acetate is widely used for oestrus control in the bitch and cat. Field reports suggested that the compound may also be used successfully in male animals for the control of undesirable behaviour. Previous surveys have indicated that the following signs or combinations of signs presented a real problem to the owners of male dogs: aggression (dominant or fear‐induced), mounting, territory marking by urination, roaming, excitability and destructiveness. In the present study the efficacy of megestrol acetate was assessed using a defined dosage regime in 163 dogs exhibiting one or more of the above signs. Seventy‐five per cent of dogs improved during treatment, and 64 per cent of dogs assessed three months after the end of treatment had maintained their improvement. The incidence of side effects was found to be low.