1 year old labrador limping out of no where?

watch for the limping again after he runs or jumps since it could be signs of hip dysplashia and it can start after running full out.my rottie was around 3 when it showed up and she started limping and wouldn't use her back leg. the xrays showed her hip poped out about 1 inch and i couldn't let her run anymore and surgery was no gaurentee since she was 135 lbs and huge.i managed to keep her comfy for a few more yrs until she could no longer walk. call ur vet if u find ur pooch having problems again . good luck