Just took DDog for a walk and a couple of times his back leg seemed to buckle under him. He didn't cry out (and he's quite a wuss so usually squeals if something's sharply painful). I cut the walk short and he now seems fine but I'm just wondering what it could be? I'm reluctant to take him to the emergency vets as he seems ok in himself but obviously will take him to the regular vet if it's still happening after the weekend. He had a big walk this morning with lots of swimming and squirrel chasing