Thank you Joan. My heart goes out to you and your lab...it is so hard, for both her and you. I have found Medicam, from the vets, does work on the pain. It was avoidable when Shamrock lost use of her back legs and we needed to keep the pain under control while we worked on her to get her walking again.
I do believe in Milk THistle for dogs and I also created a herb blend for my little boy "Blue" who is prone to seizures (another article coming up). He was having them at least once a week, having more than 52 a year. He now has perhaps 6-8. And they are less severity.
But talk to your vet about Medicam...it can take the edge off when she is having a really bad day.