get a rough yella cur and your in buisness
i got one hes 4 will catch anything 250 or under just wont hold constantly he re grips alot
I just participated in a national police K-9 competition and they had one of the top K-9 trainers in the country their to jelp guys with dog problems. one of the things i watched was regripping or (corn cobbing as he called it). What he did with this guy's 4 year old german shepherd was when the dog released to regrip run the heck away and not allow the dog to chase. After three or four drills with this that dog stayed caught. He didnt even ove his head for fear his toy wold run off.
That being said, try gettin your male to catch in a controlled environent and soon as he regrips pull the hog away and let it run off some, and not let him chase it. I havent tried this yet but i wtched it work on the GSD and i have one that regrips so i wanna give it a shot.