This afternoon when I took my dog for a walk everything was fine. When we got home and I took his leash off to let him run he darted off like he usually does and he whimpered when he did it. He stoped and tried again and whimpered again and then he wouldn't run. He has been sort all night no. Walks fine. Gets up and down fine. But he won't run, if I squeeze his two sides together (by his tail) he whimpers. He doesn't want to climb the stairs. He has never until this afternoon displayed this behavior. Could he have slept on it wrong? He is resting right now. I tried to massage his legs and he was fine with that but if I squeeze both of them he doesn't want me to touch him. Even yesterday I had him sit pretty for a treat and no problem. Today now he won't do it. I feel bad for him.