Not all the time, but over the past few days Guinness has been limping. Seems to be from his back right leg. We have checked the pads, nails etc to see if there was any injury but couldn't find any. He hasn't done anything out of the ordinary lately...no long walks or excessive exercise - just regular nightly retrieves and walks with hubby. Do dogs get pulled muscles like humans do? I'm guessing its something like that...maybe he slipped on some ice while running or pulled something. Seems a little lethargic but everything else okay. What do you guys think?