Thanks for the reply.
She wasn't checked for Lyme disease but it was mentioned during the exam. I'm assuming that if she does end up back in the vet's office there will be blood work done up as well as the x-ray.
As far as Rimadyl is concerned , after 3 1/2 days there's no signs of any adverse reaction. She's eating well (in fact almost better than before

) but I'm only keeping her on it for the prescribed time as it's not on;ly a pain reliever but an inflammatory drug as well.. If she needs long term pain medication for relief I'm looking elsewhere.
As for being in pain with no medication , she's not whimpering or anything but her eyes don't have that sparkle and she simply looks distressed (other than the bored expression. Part Border Collie

)
She had a very mild limp for quit a while (off and on) and I mentioned this to the vet. His reason for dismissing arthritis as the cause during the exam was that for arthritis to cause such a severe limp , there would have been a very noticeable feel in the shoulder during manipulation. He didn't rule it out entirely and said only an x-ray would be definitive but at a cost of $125.00 (cost isn't a factor when it comes to our pets) and the fact there was no one in the office to perform the x-ray , he felt the 2 week trial might be worth a go.
But thanks for the insight and the heads up about Lyme disease. I will read up on it and become informed and make sure the vet checks it out if we need to.