I had a Labrador he was a large boy and he was my heart, but he developed arthritis early on in life. At the advice of my vet I started him on Rymadil at the age of 6. My vet at the time did not tall me he needed to have his liver monitored yearly to see the toll that Rymadil could take on it. At the age of 9 he went for a routine tooth cleaning and had to have blood work done, he had cancer. I was devastated. After an ultrasound of his liver, which by then looked like swiss cheese, the new vet told me it was most likely the Rymadil that did it to him. I was pissed, I felt like I was given a drug to give my dog without being told what it could do to him. I lost him six months after that and it was devastating. I have three labs now and I vowed I would never again give them Rymadil and I would not give them a drug without serious questions of what could happen to them down the road. Just because they are dog and not people doesn't mean they deserve any less to me. Thanks for listening hope this helps someone else with an ageing lab. Here is a pic of the old man.
So sorry for your loss. But please don't beat yourself up or your vet too much about this. Certainly they should have told you about the liver issues with Rimadyl so maybe you could have changed to a different drug but there are quality of life issues too.
Terrified (because I knew about those issues) we tried every other drug to control my old boys pain and we finally tried Rimadyl as a last resort and it worked so much better than any other drug. Might it have contributed to his death...certainly...but he lived his life MUCH happier. I'll take a quality of life over quantity of life anyday. Besides...cancer is the leading cause of death in dogs and liver cancer is a biggie....it may or may not have been the Rimadyl.
You did what you could for your buddy. We do what we can with what we know...
There are a lot of holistic things you can try before resorting to NSAIDS. I am so sorry for your loss. I too have a fear of Rimadyl. Tramadol can help and is less invasive. However, I prefer to try holistic first. See info at the link below. Keep in mind that with holistic it can be a combination of things that work.