my pups just turned 9 month. up untill a month ago,he showed absolutely no interest in chasing anything! game,balls,sticks!nothing. but a month ago he changed,he's like a different dog,he wants to be into anything.his prey drive has just appeared from nowhere and he's keen as hell! and he was also a bit timid before,now he has no fear of anything!lol. so,just be patient mate.the dog will let you know when he's ready!and if he's anything like my dog,he'll make it obvious!