[107barney]

If my vet prescribed Rimadyl for my dog, I would not hesitate to use it.
As for the "disk problem" - this can range from being treatable with meds and keeping activity down or it can be severe requiring surgery. On two occasions, I have had one of my yorkies in a similar position and crating the dog w/ anti-inflammatory medication for 4 weeks allowed the disk to heal. With the symptoms you describe, I think I would make a trip to Ocean State Veterinary Specialists for a visit with the neurologist there. I don't know the neurologist there but I know they have one (it appears they have not updated their website). Keep us posted.