Is It Safe to Give a Dog Glucosamine Chondroitin for Arthritis?

Glucosamine & Chondroitin has worked great for my dogs arthritis. We were told she needed to be on Rimadyl but it wasn't doing anything. I give her 2 pills a day of Vitamin World Joint Soother and she has done a complete turn around after only a couple of weeks. It's been a year that she's been on these and I'm so glad that it's helped as much as it has. I've heard that the liquids work very well since they get in the system much quicker.