Hope Karla right or possible nerve or muscle
injury.
Was thinking possible degenerative myelopathy but that would probably be the worst case scenario.
Is he holding the leg up or is he actually dragging the leg? Here's what to do:
Stand him up on all four legs...Turn the bad foot under where he's standing on top of the paw....See if he can flip it back to the correct position.....If not: Read further.....
This sounds like a disk injury to me......Google IVDD (Intervertabral Disk Disease) and read about it...Let us know, Karla
Though older, my daughter's dog has been doing this for a while but I can't recall what he said it was. Possibly something spinal. I will keep trying to get in touch with her. Does not seem to be particularly painful. Does your dog seem to be in pain?
Have you tried palpitating his leg and flexing it slowly? Just like when you twist your ankle and need to stretch it out. There are 4 joints: hip, knee, hock, and ankle. Check each of them.