Ok -- thanks
Lame for 3 weeks is a significant time. Have x'rays been taken?
Dogs that hang a back leg and won't put it down or put it down very gingerly often have stifle problems. Did the vet localize the problem to the pelvis or a specific part of the leg?
You said the chiropractor found soft tissue/muscle pain along the thigh. This is compatible with stifle pain. Stifle injuries usually occur after jumping up to catch something, jumping in or out of a truck, etc.
The leg becomes weight bearing and twists at the stifle putting stress on the anterior cruciate ligament. This is an extremely common problem in dogs and Labs seem to be particularly prone perhaps because they are generally very active.
The vet did not identify any thing specific - just that the issues appeared to be in lower back/hip area.
No xrays have been taken.
The dog regularly runs like a manic -- loves to chase the ball, deer, turkeys, whatever uphill/downhill (we live in the hills).
What should I do now?
Given the 3 weeks since this occurred, you are past the wait and watch phase.
I would recommend getting a diagnosis. If there is an orthopedic specialist or a vet with orthopedic exam and treatment skills in your area, start there. You should be able to ask your vet and get a referral. I'm suggesting this because you need someone who has experience with orthopedic injuries and trained hands to do the physical exam part of the diagnosis and determine what needs to be x'rayed. I'm suggesting going through your regular vet because it keeps him/her in the loop and is a learning opportunity.
Depending on the findings of the exam, x'rays of the hind leg/stifle and pelvis are likely to be needed.
Soft tissue injuries require rest to heal. Stifle anterior cruciate ruptures do best with surgery. It doesn't sound like a long bone fracture - both the vet and chiropractor would have found it, but hips and stifles can have other bone/ligament damage.
Keep him quiet or as quiet as possible. I'd give rimadyl and not tramadol, but have only my personal preference for that statement. I think that orthopedic injuries are inflammatory and rimadyl treats inflammation. Tramadol treats only pain.
I would very much appreciate knowing the outcome if possible.
I wish you and your crazzy dog the best. I have a bunch of crazzy Dobes and love to see then in action.
Let me know if you have further follow up questions.
I appreciate you taking the time to give me an update. Neurologic problems can be hard to diagnose and hard to treat.
I am very sorry that you lost Ringo.