Hip issues Big Dogs... 2nd opion? *NEW update 10/17

Poor Duke has been to the vet. Right now they are saying the pain is arthritis. And no muscle in one of his hips. He was walking on it with pressure but gingerly. They ruled out Valley Fever and anything being broken or sprained.He had no fever period. Eats fine and every other way seems normal.  He had started on the Melocoxicam and Glucosamine  and now we've added the Tramadol. We're doing two just to get the pain under control. They even gave him a pain shot because he was really hurting when they were checking him over. That helped take the edge off and they could check his nails and everything without sedation. Thought for sure they were going to so they could figure it out.
  But since we've been to his last visit (which was Monday) his legs seems to have gotten worse. He does not get up unless we bribe him. That scares me. We're also altering between heat packs or ice packs. He seems to like the ice better.  Do I take him back in and go the next step for more blood work? Or wait and see if the meds work? They said it can take up to two weeks before the meds really start to help. Today his pains better but his walking is not. His poor leg just gives out on him. You can tell it frustrates him. Dh has had to try to help him up once or twice but he wants to do it on his own. He's 5 almost 6. It seems awfully young for hip issues already. He does get up on our small sofa just fine but has some trouble getting down. I try not to let him if I can catch him. I haven't figured out how to block it totally off. He also did a poop when he stepped on the scale at the vet. They were relieved that he poops ok. lol and it was normal.

What have you tried that works if you've been through this with your furry ones?
Can I ask the age of your pet if they started getting issues? Our friends dog got it a lot later. He was a black lab too.
Should I wait and see how he mends or get a sec opinion even? Dh asked that last night? I am hoping once the pain is under control we can work on the muscles. Doc said to have him walk up and down the hall when he can. Not doing walks just yet.

**SmUpdate 10/13 Duke is doing a little better today. He has a good appetite and has been drinking like a fish since we took him off the tramadol. It was rough night though for all of us because he didn't know what was going on. He did try to drag himself down the hall so he could come to bed with us, he would not let us help him. I even slept on the floor for some of the night with him so he wouldn't try to come down. But he wanted to be in by his bed. And that just wears him out. 
  I talked to the vet we're going to switch out the melixicam for prednisone and and other muscle relaxer. (I can't remember the name) He says its good he's responsive and alert he just didn't tolerate the tramadol well.So we're hoping he does better with the two new ones. He's still doing the supplements as well.  I alter between heat and ice and massaging his back and legs. That helps a lot. Vet said it was also good he's responding to the massages.And has his senses. I hope we can control this . 
 And thank you for sharing your experience! It really does help! 

**NEW UPDATE 10/17 We finally have his pain under control. He's on muscle relaxers and one-three tramadol depending on how he does. Friday and Sat were rough so we took him in Sat morning. I thought something was very wrong. He was not responding at all. We had to lift him in a sheet to get him in and out of the car. It took three people to help us get him out of the car. 
  We tested him for Lyme disease. We don't normally get the ticks here but Dh had been camping and and we had been out of state but it had been a while. However we had a cousin who had also been and he was the one who stayed with them them when we went out of state. It was when we got back we noticed the decline. 
 I got the call about an hour the test was very positive for Lyme disease. Even the vet was relieved and shocked as us. Our other concern was that he had a spine issue. IVDD.  On Sat we started him on the antibiotics. He still had a rough day yesterday but today he seems to be doing much better. He actually stretched out his back legs this morning. Dr said we hopefully caught it early enough and can treat it. It's about a four-six week recovery. He'll see him again in 10days when he runs out of antibiotics and see if we need to up them them or keep him on them and the pain meds and reevaluate him then.