Occasional limp

Question
We have a two and a half year old Airedale.  We think she may have sprained or strained her left rear leg during playtime a couple weeks ago.  That's when we first noticed the condition.  When she gets up after resting she occasionally favors the leg for a few steps then regains a normal gait.  There is no "crying" involved and she continues happily when her muscles "warm up".  

Answer
A sprain would not last that long unless she partially tore her knee ligament.  She may have a bit of hip dysplasia or athritis....I would recommend an x-ray to check for sure.  Otherwise get her started on Glucosamine and MSM joint supplements to help keep her joints lubricated.