Thanks for all your thoughts.

I should clarify though- Sara is still at the vet. She had the ultrasound this morning and we're still waiting to hear the results.

I think part of the concern about the ultrasound is that as of yesterday the bill was at $1200. It's hard to know how much money to put into a 12 year old dog who may not survive no matter what is done. If the ultrasound shows a gall bladder problem the only option is surgery which we probably wouldn't do anyway. As it turned out the vet really wants the information and offered not to charge for the ultrasound (I think they feel responsible given that the rimadyl started things).

As for other pain medicines- my experience with my own dog is that aspirin made her vomit and glucosamine didn't help. She started taking rimadyl and was suddenly bouncing off the walls (well maybe just jumping on the bed but you get the idea). I don't think it was a bad idea to try it in Sara- we just got unlucky. As for the lab tests- they didn't do any before starting the drug (the idea was to see if it helped and then monitor the liver function if she was going to stay on it). It does seem like overkill to test every dog's blood before starting an NSAID, but on the other hand we'd have known if Sara had some sort of pre-existing liver/ gall bladder condition.