Hind Leg problem with my GSD

Question
MY MALE GSD IS 7 MTHS OLD. NOT BEEN SPAYED.

WHEN HE IS WALKING, HE SEEMS TO BE FLAYING HIS RIGHT HIND LEG.

WHAT COULD BE THE PROBLEM


THANKS

Answer
That could be several things, some of which he will grow out of and some little can be done.  If possible, have him examined by a vet.  

You should be feeding an adult chow now. Switching to an adult chow for the larger breeds rsrly, slows growth and helps develop sturdier joints.  Overweight is a bigger problem forthe same reason.

Your dog definitely should be narrower at the waist than the hips and chest. You should be able to easily feel the ribs, but not see them. Each dog is different. Standard recommendations are a good place to start, but each dog must have its food and exercise adjusted to its individual needs. Here is a link to a good illustrated guide, http://www.longliveyourdog.com/twoplus/RateYourDog.aspx