
It sounds as though it may be hip dypslasia but the only way that you are going to truly find out whether it is or not is by having him x-rayed. It may be just that he's pulled a muscle too, but without an x-ray you won't really know.
I can tell you now that after having a working dog who wasn't allowed to do any walking for 8 weeks it's a lot easier than you think if you've got a big crate that you can put them in. I was dreading the total rest but she coped brilliantly.
If you've got a cage put him in there though only whilst you are around if he's not used to being caged and see how he goes for the next couple of weeks.