My dog refuse to move in the middle of a walk

[4petAbank.]

My dog is 75 pounds GSD (9 months). He stop walking all the time during our walk, and I had to pull, even drag him behind me. I noticed some time he stopped because he wants to sniff the bushes on the side of the road. But some time, there's nothing around, and he just simply stopped, stand still, don't move at all. It is getting very annoying recently, he's almost stopped after ever few minutes, I asked the vet, maybe he has hip problem, She said he is too yound, should not, also when he's walking, he looks normal, no limping, or stiff legs. Now our daily walk is like a battle. What should I do, And what made him behave like this? He was walking pretty good before.

[harvey2k11]

got a 6 month old chocolate labrador called harvey, we have 1 problem with him at the moment recently, he goes for his walks no problem, but we live opposite a large field but have to cross a road to go out and come home, so just before the road we attatch his leader and he walks so far coming home, we get 100 metres away from home and he stops and refuses to move?

we have tried tempting him home with treats and rewarding him when he eventually gets home, but he has now got wise to this and now refuses to take the treats

any help is appriciated