Originally Posted by DanL
If his front legs are trembling when he lifts is back leg, maybe its a balance thing. Like when someone learns how to bench press their arms shake even though they are strong enough to hold the bar up.
The limping thing could be pano. Gunnar had that from about 8-9 months till he was about 15 months or so. It'd flare up from time to time and you'd see him favoring that leg. It was a sore spot right in the middle of his forearm, you could find it by pressing down the leg. Our vet had us give him a regular asprin when it flared up to help with the inflammation and irritation. It didn't cause him to not want to exercise and play, we had to keep him calm and do things that were more mental games than physical when it was flaring up.
It may very well be balance. He's got really long legs and is incredibly clumsy even by lab standards.
I've not heard of pano, but I think his limping is probably related to his exercise level. When I go on travel, we hire a guy to take Manni out hiking for 2-3 hours in the afternoon. If I'm gone for an entire week, by the end of the week Manni is limping pretty noticeably. He typically will stop limping after a few days. Also, I should have mentioned that he's ~5 years old.