I wanted to post this, just in case the info is worth anything to others. Heidi is almost 13 and has HD pretty bad. I am afraid she won't be with us too much longer, which is the reason I was questioning whether she really needed bloodwork before regular Rimadyl. I spoke with my vet this morning and told him my concerns and questions. He said that the kidney/liver damage that could occur could feasibly cause problems in maybe 3 months, not so very long term. Since I don't want Heidi to be sick, I did agree to the bloodwork to check.