Limping French bulldog puppy

Question
Hi,
My 11 month old, 23 lb. Frenchie started favoring his left rear leg about three weeks ago after running around the yard. The x-rays looked normal, and acupuncture actually seemed to help for the first few days after treatment. He can't jump up at all, he only lays on his left (hurt) side, and he yelps if you roll him onto the right, pick him up wrong, or pull the leg straight back when he's laying down on his stomach. Sometimes when it seems really sore (after a nap, etc.) he shivers all over and we have to put a blanket on him. The vet has him on Tramadol with orders to just watch him for a while. She thinks it might either be Femoral Head Necrosis or a really bad sprain. I guess I have two questions: 1) I hate the waiting game. How much longer should I let it go before we do more tests? and 2) What's up with the uncontrollable shivering?

Answer
This is probably a patella injury and as long as the patella is still in place, he will heal, but it's a lengthy process.

First of all, the dog should be kept as quiet as possible while he is in pain.  That means crate rest and leash walking only, no playing, no jumping, no nothing. The shivering is a pain response. Once the pain is gone, or at least not debilitating, then you can start doing some stretchening work with him, longer walks. The key it to build up the tendons and muscles in that area so they can support the patella without injuring it again.

This may take months to resolve.