Funny walking puppy

Hey people, i was just @ a friends place, hes got a 5 month old pbt , and it walks funny in the rear, like its constipated or something, it doesnt look natural, even when she runs/trots it looks strange lol, any ideas on if its natural or is theres a known commen problem with hind-quaters...?

 

Hip dysplasia? Though that doesn't often show up in young dogs, usually only in more severe cases, but it's possible. Could also be luxating patellas (where the kneecap slips in and out of place as the dog walks), but that too is pretty uncommon in young dogs. It could also be just puppy ganglies causing an awkward gait. If they're going to be putting the pup under anesthesia for anything, it couldn't hurt to have some films done of its back end, just to be sure if the pups gait doesn't even up with time.

 

Thanks for ya feedback, it doesnt look painful too her but made me question him about her walkin funny and what he'd done about it, which was nothing, so hes takin her to the vet for a general checkup etc..